The coils are wound with copper wire (covered with silk), 10 mils.
The coils are wound with copper wire (covered with silk), 10 mils.
It's so much more effective than rope, or wire, or chains.
For a wire exposed under the conditions observed by Elster and Geitel the emanation seems to be almost entirely derived from radium.
Some of the containers had a thin wire running around but most were standing alone.
It is essential that the paper covering be loose, so as to ensure that each wire is enclosed in a coating not of paper only, but also of air; the wires in fact are really insulated from each other by the dry air, the loose paper acting merely as a separator to prevent them from coming into contact.
The coated wire is treated in the same way as the copper strand - the die D, or another of the same size, being placed at the back of the cylinder and a larger one substituted at the front.
The description of that vehicle is plastered at every toll booth, state police barracks and wire service from here to California and back.
Can't you just wire Julie a ticket and make arrangements for her to get to the airport?
Thus, if the star's image is kept in bisection by the wire, both star and wire will appear at rest in the field of view.
However, the Wizard went once more to his satchel--which seemed to contain a surprising variety of odds and ends--and brought out a spool of strong wire, by means of which they managed to fasten four of the wings to Jim's harness, two near his head and two near his tail.
18, where L is the line wire, joined through the 7 t?
3 The surrounding silver was then dissolved by nitric acid, and a platinum wire of extreme fineness remained.
Connexion is made into the office (or to the underground system, as is often the case) from the aerial wire by means of a copper conductor, insulated with gutta-percha, which passes through a " leading in " cup, whereby leakage is prevented between the wire and the pole.
Connexion is made into the office (or to the underground system, as is often the case) from the aerial wire by means of a copper conductor, insulated with gutta-percha, which passes through a " leading in " cup, whereby leakage is prevented between the wire and the pole.
The radioactivity is denoted by A, and A = signifies that the potential of the dissipation apparatus fell I volt in an hour per metre of wire introduced.
His determinations of pitch by a weighted wire are not trustworthy; Ellis thinks they are not safe within four or five vibrations per second, but gives a mean pitch for this organ, when altered, of a' 395.2.
in.; the test strain required for the iron wire is about 222 tons.
4); a current is sent from a battery, E, through one coil of a galvanometer, g, through a high resistance, r, through one of the wires, r, and thence back from office B (at which the wires are looped), through wire 2, through another high resistance, r', through a second coil on the galvanometer, g, and thence to earth.
His determinations of pitch by a weighted wire are not trustworthy; Ellis thinks they are not safe within four or five vibrations per second, but gives a mean pitch for this organ, when altered, of a' 395.2.
4); a current is sent from a battery, E, through one coil of a galvanometer, g, through a high resistance, r, through one of the wires, r, and thence back from office B (at which the wires are looped), through wire 2, through another high resistance, r', through a second coil on the galvanometer, g, and thence to earth.
The iron wire used for wire-netting, telegraphic purposes, &c., is commonly galvanized, as also are bolts, nuts, chains and other fittings on ships.
to the piston P. The newly coated wire is passed through a long trough T, containing cold water, until it is sufficiently cold to allow it to be safely wound on a bobbin B' This operation completed, the wire is wound from the bobbin B' on to another, and at the same time carefully examined for air-holes or other flaws, all of which are eliminated.
This cone is driven by gearing from the wire drum, so that it rotates at the speed of the outgoing wire, the direction of rotation being such as to cause the nut to travel towards the smaller end of the cone.
After a jotted message to his wife who was back on the wire, Dean was on his way.
It is, however, more commonly and familiarly called " the wire " or " the line."
As Josh climbed into his truck, Alex raised the hood and jerked a wire loose.
Each movable web must pass the other without coming in contact with it or the fixed wire, and without rubbing on any part of the brasswork.
It should be mentioned that an essential feature of the travelling wire micrometer is that the eyepiece as well as the wire shall be moved by the micrometer-screw.
On one of them I noticed that the strings were of wire, and having had some experience in bead work, I said I thought they would break.
The sizes of copper wire employed have weights of too, 150, 200 and 400 lb per statute mile, and have electrical resistances (at 60° F.) of 8.782, 5.8 55, 4.39 1 and 2.195 standard ohms respectively.
Copper wire weighing 600 and 800 lb per mile has also been used to some extent.
She shooed the goat back into the pasture and grabbed a pair of linesman pliers and some bailing wire from the barn.
The subsidiary industries, such as the manufacture of machinery and wire fabric, are of considerable importance.
By the time she reached the cliff Jule indicated the next day, Yully's soul was humming like an electric wire.
This loss is proportional to the length of the wire.
An important modern application of the micrometer, which is not dealt with in the article Transit Circle, is that which is now called " the travelling wire micrometer."
The particular sizes and descriptions of wires used are dependent upon the character of the " circuits " the longer and more important circuits requiring the heavier wire.
The earth is always, except for some special reason, used as a return, because it offers little resistance and saves the expense and the risk of failure of the return wire.
Duplex telegraphy consists in the simultaneous transmission of two messages, one in each direction, over the same wire.
Delany (which was adopted to a limited extent in Great Britain, but has now been entirely discarded) had for its object the working of a number of instruments simultaneously on one wire.
The general graphy, principle Arms a and arrangement b, one at eachstation and d B, are connected to the line wire, and are made to rotate simultaneously over metallic segments, 3, 4, and I', 3', 4', at the two stations, so that when the arm a is on segment i at A, then b is on segment I' at B, and so on.
The system brought out in 1874 by Emile Baudot and since considerably developed is a multiplex system giving from two to six channels on one wire, each channel giving a working, speed of thirty words per minute.
One of the longest circuits upon which it has been successfully worked is that between St Petersburg and Omsk, a distance of approximately 2400 miles of iron wire, with three repeating stations.
In what is known as the " hybrid " form of recorder the permanent magnets are provided with windings of insulated copper wire; the object of these windings is to provide a means of " refreshing " the magnets by means of a strong current temporarily sent through the coils when required, as it has been found that, owing to magnetic leakage and other causes, the magnets tend to lose their power, especially in hot climates.
or similar undertakings, and to obviate this it is necessary to form the " earth " for the cable a few miles out at sea and make connexion thereto by an insulated return wire, which is enclosed in the same sheathing as the core of the main cable.
ance coil of some 2000 turns of insulated copper wire, enclosed in a laminated iron circuit, and connected at intervals to a number of terminals so that equal increments of inductance may be obtained.
This consists of a low resistance coil of copper wire enclosed in a laminated iron circuit similar to the magnetic shunt already de Magnetic scribed.
of wire and about 200 m.
He proposed that one ship should be provided with the means of making an interrupted current in a circuit formed partly of an insulated metallic wire connected with the sea at both ends by plates, and partly of the unlimited ocean.
Canal system of flow lines of current through the sea, and these might be detected by any other ships furnished with two plates dipping into the sea at stem and stern, and connected by a wire having a telephone in its circuit, provided that the two plates were not placed on the same equipotential surface of the original current flow lines.
The shore wire was 1267 yds.
A wire 750 yds.
By stretching on the island and mainland parallel wire circuits earthed at each end, good telephonic communication over an average distance of 62 m.
He proposed to employ two large flat coils of wire laid horizontally, on the ground, that on the mainland having in circuit a battery, interrupter and key, and that on the island a telephone.
p. 203) noticed that a single electric spark about an inch long thrown on to a circuit of wire in an upper room could magnetize steel needles included in a parallel circuit of wire placed in a cellar 30 ft.
He employed as a detector of this wave a simple, nearly closed circuit of wire called a Hertz resonator, but it was subsequently discovered that the metallic microphone of D.
plate E and the other to a plate or wire insulated at the upper end and elevated above the surface of the earth.
This elevated conductor is now called the antenna, aerial wire, or air wire.
38 6), the insulated wires or plates being upheld by masts, its operation is as follows: - When the key in the primary circuit of the induction coil is pressed the transmitting antenna wire is alternately charged to a high potential and discharged with the production of high frequency oscillations in it.
The antenna wire, connected to one spark ball of the induction coil, must be considered to form with the earth, connected to the other spark ball, a condenser.
When the discharge takes place the ends of the lines of electric force abutting on the wire run down it and are detached in the form of semiloops of electric force which move outwards with their ends on the surface of the earth.
If we consider the lines of magnetic force in the neighbourhood of the receiving antenna wire we shall see that they move across it, and thus create in it an electromotive force which acts upon the coherer or other sensitive device associated with it.
First as regards the transmitting part, one essential element is the antenna, aerial, or air wire, which may take a variety of forms. It may consist of a single plain or stranded copper wire upheld at the top by an insulator from a mast, chimney or building.
The wire may have at the upper end a plate called a " capacity area," electrically equivalent to an extension of the wire, or part of the wire may be bent over and carried horizontally.
jars or of Leyden panes immersed in oil or some form of air condenser, and the inductance coil or primary circuit of the oscillation transformer consists of a few turns of highly insulated wire wound on a frame and immersed in oil.
In its course it passes through a glass tube wound over with two coils of wire; one of these is an oscillation coil through which the oscillations to be detected pass, and the other is in connexion with a telephone.
A fourth class of electric wave detector comprises the thermal detectors which operate in virtue of the fact that electric oscillations create heat in a fine wire through which they pass.
If a loop of very fine platinum wire, prepared by the Wollaston process, is included in an exhausted glass bulb like an incandescent lamp, then when electric oscillations are sent through it its resistance is increased.
This increase may be made evident by making the loop of wire one arm of a Wheatstone's bridge and so arranging the circuits that the oscillations pass through the fine wire.
47) and when electric waves fall on A they excite oscillations in the fine wire resistance R and increase the resistance, and so upset the balance of the bridge and cause the galvanometer to deflect.
Fessenden employed a simple fine loop of Wollaston platinum wire in series with a telephone and shunted voltaic cell, so that when electric oscillations passed through the fine wire its resistance was increased and the current through the telephone suddenly diminished (R.
He passed the oscillations to be detected through a fine wire or strip of gold leaf, and over this, but just not touching, suspended a loop of bismuth-antimony wire by a quartz fibre.
This loop hung in a very strong magnetic field, and when one junction was heated by radiation and convection from the heating wire the loop was 18 See R.
In the inner space between the test tubes one pair of these platinum wires are connected by a fine constantan wire about 02 mm.
The other pair of platinum wires are connected by a tellurium-bismuth thermo-couple, the junction of which just makes contact with the centre of the fine wire.
The thermal G G detectors are especially useful for the purpose of quantitative measurements, because they indicate the true effective or square root of mean square value of the current or train of oscillations passing through the hot wire.
This plate is supported by a platinum wire sealed through the glass.
Wehnelt discovered that the same effect could be produced by using instead of a carbon filament a platinum wire covered with the oxides of calcium or barium, which when incandescent have the property of copiously emitting negative ions.
A highly insulated tube contains a little mercury, which is used as a negative electrode, and the tube also has sealed through the glass a platinum wire carrying an iron plate as an anode.
a b, constantan wire; c d, thermojunction; G G, galvanometer terminals; 0 0, antenna and earth terminals.
His transmitter consists of a nearly closed oscillating circuit comprising a condenser or battery of Leyden jars, a spark gap, and the primary coil of an oscillation transformer consisting of one turn of thick wire wound on a wooden frame.
To the outer end of this lateral wire a condenser was attached and the coherer inserted between the condenser and the earth.
At St John's in Newfoundland he erected a temporary receiving antenna consisting of a wire 400 ft.
The capacity of the condenser is then altered until the maximum current, as indicated by a hot wire ammeter, is produced in the circuit.
ical tele- Two disks of thin metal, or two stretched membranes, each furnished with a mouthpiece, are connected together by a thin string or wire attached at each end to the centres of the membranes.
Gray's and then either to earth or back to the induction coil by a return line of wire.
A single line of wire, like an ordinary telegraph line, had a Bell telephone included in it at each end, and the ends were put to earth.
The resistance of the microphone can thus be made a large fraction of the total resistance of the circuit in which it is placed; hence by using considerable currents, small variations in its resistance can be made to induce somewhat powerful currents in the line wire.
The spring-jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.
This requirement is usually met by connecting a third or " test " wire to each of the jacks associated with a subscriber's line, and by making the circuit arrangements such that this wire is either disconnected or at earth potential when the line is not in use, and at some potential above or below that of the earth, when the circuit is engaged.
When a subscriber at exchange A asks for a connexion to a subscriber at B, the operator at A, to whom the request is made, passes the particulars over an order wire to an operator at B.
The four telephones on a circuit are so wired that the relays 9-- P ..,, connect two of the bells between each wire and fl-- 0 7-..9 *"y earth, and further that one of each pair of bells responds to positive and the other to negative o-- pulsations.
As subscribers' lines are invariably short, the smallest gauge of wire possessing the mechanical strength necessary to withstand the stresses to which it may be subjected can be employed, and bronze wire weighing 40 lb per mile is commonly used.
The introduction in 1883 of the hard-drawn copper wire of high conductivity invented in 1877 by T.
Wire weighing between 150 and 400 lb per mile is generally used.
The New York-Chicago line, built in 1892, is of wire 165 millimetres in diameter (No.
Large as this progress was it would have been much greater if the Telephone Company had been granted adequate powers to put wires underground and thus instal a complete metallic circuit in place of the single wire, earthreturn, circuit which it was constrained to employ.
The Postmaster-General agreed also to buy the private wire plant of the company at a value based upon three years' purchase of the net profits on the average of the three years ending 31st of December 1911.
The Postmaster-General also agreed to lay underground wires for the company at an annual rental of L1 per mile of double wire in any local area in which the company was operating, but not in areas in which the municipalities had established exchanges.
The number of trunk wire centres open on the 31st of March 1907 was 533, and the total number of trunk circuits was 2043, containing about 73,000 m.
of double wire.
The capital expenditure on the purchase and development of the trunk wire system amounted to £3,376,252.
of wire had been laid, including 69,066 m.
Much has been done in keeping out the insects by fine wire netting placed on the windows and the doors of houses, especially in the railwaymens cottages.
The chief manufactures are paper and wire, and from the quarries near the village of Lee is obtained an excellent quality of marble; these quarries furnished the marble for the extension of the Capitol at Washington, for St Patrick's cathedral in New York City and for the Lee High School and the Lee Public Library (1908).
In two peasants' cottages in the Campagna, protected with wire netting by Professor Celli, all the inmates-10 in number - escaped, while the neighbours suffered severely; and three out of four persons living in a third hut, from which protection was removed owing to the indifference of the inmates, contracted malaria.
When a place cannot be kept free from mosquitoes the house may be protected, as in the experiments in Italy, by wire gauze at the doors and windows.
The arrangement used for the entrance is a wire cage with double doors.
Besides the royal foundry, with which are connected machine manufactories and boilerworks, there are other foundries, meal mills and manufactories of wire, gas pipes, cement and paper.
the early stages if the entrance of the caterpillars has been detected, a wire should be pushed into the hole.
Across the river is Rock Falls (pop. in 1900, 2176), practically a suburb of Sterling, with foundries and machine-shops and manufactories of agricultural implements, barbed wire and bolts and rivets.
plain-laid manila cable a wire rope has in some cases been successfully substituted.
An alternating current of one ampere is defined to be one which produces the same heat in a second in a wire as the unit continuous current defined as above to be one ampere.
In their simplest form they consist of a wire through which passes the current to be measured, some arrangement being provided for measuring the small expansion produced by the heat generated in the wire.
This may consist simply in attaching one end of the wire to an index lever and the other to a fixed support, or the elongation of the wire may cause a rotation in a mirror from which a ray of light is reflected, and the movement of this ray over a scale will then provide the necessary means of indication.
It is found most convenient to make use of the sag of the wire produced when it is stretched between two fixed points (K 1 K 2, fig.
To render the elongation evident, another wire is attached to its centre S2, this last having a thread fixed to its middle of which the other end is twisted round the shaft of an index needle or in some way connected to it through a multiplying gear.
The expansion of the working wire when it is heated will then increase or create a sag in it owing to its increase in FIG.
In order that this may take place, the heated wire must be flexible and must therefore be a single fine wire or a bundle of fine wires.
In ammeters for small currents it is customary to pass the whole current through the heating wire.
In instruments for larger currents the main current passes through a metallic strip acting as a bye-pass or shunt, and to the ends of this shunt are attached the ends of the working wire.
This shunt is generally a strip of platinoid or constantin, and the working wire itself is of the same metal.
There is therefore a certain ratio in which any current passing through the ammeter is divided between the shunt and the working wire.
This is done by mounting the working wire on a metal plate made of the same metal as the working wire itself; thus if the working wire is of platinoid it must be mounted on a platinoid bar, the supports which carry the ends of the working wire being insulated from this bar by being bushed with ivory or porcelain.
Then no changes of external temperature can affect the sag of the wire, and the only thing which can alter its length relatively to the supporting bar is the passage of a current through it.
Hot-wire ammeters are, however, liable to a shift of zero, and means are always provided by some adjusting screw for slightly altering the sag of the wire and so adjusting the index needle to the zero of the scale.
The reason is that the heat produced in a given time in a wire is proportional to the square of the strength of the current passing through it, and hence the rate at which the heat is produced in the wire, and therefore its temperature, increases much faster than the current itself increases.
In the construction of such an instrument it is essential that the wire should be subjected to a process of preparation or " ageing," which consists in passing through it a fairly strong current, at least the maximum that it will ever have to carry, and starting and stopping this current frequently.
The wire ought to be so treated for many hours before it is placed in the instrument.
It is also necessary to notice that shunt instruments cannot be used for high frequencies, as then the relative inductance of the shunt and wire becomes important and affects the ratio in which the current is divided, whereas for low frequency currents the inductance is unimportant.
In constructing a hot-wire instrument for the measurement of high frequency currents it is necessary to make the working wire of a number of fine wires placed in parallel and slightly separated from one another, and to rpass the whole of the current to be measured through this strand.
If a small alternating current is passed through one wire, it sags down, the mirror is tilted, and the spot of light on the screen is displaced.
It consists of a glass bulb, in which there is a loop of fine wire, and to the bulb is attached a U-tube in which there is some liquid.
When a current is passed through the wire, continuous or alternating, it creates heat, which expands the air in the bulb and forces the liquid up one side of the U-tube to a certain position in which the rate of loss of heat by the air is equal to the rate at which it is gaining heat.
In its simplest form an electromagnetic ammeter consists of a circular coil of wire in which is pivoted eccentrically an index needle carrying at its lower end a small mass of iron.
When a current is passed through the coil the iron tends to move nearer to the coil of the wire where the field is stronger and so displaces the index needle over the scale.
Another type of similar instrument consists of a coil of wire having a fragment of iron wire suspended from one arm of an index needle near the mouth of a coil.
When a current is passed through the wire forming the coil, the fragment of iron is drawn more into the aperture of the coil where the field is stronger and so displaces an index needle over a scale.
In those intended for alternating currents, the main current through the movable coil, whether consisting of one turn or more than one turn, is carried by a wire rope, of which each component strand is insulated by silk covering, to prevent the inductive action from altering the distribution of the current across the transverse section of the conductor.
Heat the substance with a bead of microcosmic salt or borax on a platinum wire in the oxidizing flame.
Hold a small portion of the substance moistened with hydrochloric acid on a clean platinum wire in the fusion zone' of the Bunsen burner, and note any colour imparted to the flame.
Beilstein determines their presence by heating the substance with pure copper oxide on a platinum wire in the Bunsen flame; a green coloration is observed if halogens be present.
Attached to the bulb was a glass rod and then a tube containing iron wire.
They were employed as animated roasting jacks, turning round and round the wire cage in which they were confined, but with the employment of mechanical jacks their use ceased and the race appears to be extinct.
of copper wire had been set up, with such satisfactory results as to awaken the practical interest of the Messrs Vail, iron and brass workers in New Jersey, who thenceforth became associated with Morse in his undertaking.
Paper, spirits, wire and nails, leather and tiles are the chief products of the manufactures.
The observatory, which was connected by wire with the post office at Fort William, was provisioned by the Scottish Meteorological Society, to whom it belonged.
More steel wire, wire nails, and bolts and nuts are made here than in any other city in the world (the total value for iron and steel products as classified by the census was, in 1905, $42,930,995, and the value of foundry and machine-shop products in the same year was $18,832,487), and more merchant vessels than in any other American city.
There are also in the city several large grain mills and breweries, a biscuit factory, wire and hemp roperies, fuel works, general foundries and engineering works.
When two metallic conductors are placed in an electrolyte, a current will flow through a wire connecting them provided that a difference of any kind exists between the two conductors in the nature either of the metals or of the portions of the electrolyte which surround them.
When the zinc and copper plates are connected through a wire, a current flows, the conventionally positive electricity passing from copper to zinc in the wire and from zinc to copper in the cell.
It is a centre of the iron and steel industries, producing principally cast steel, cast iron, iron pipes, wire and wire ropes, and lamps, with tin and zinc works, coal-mining, factories for carpets, calcium carbide and paper-roofing, brickworks and breweries.
In the evening the milk is strained through a wire sieve and transferred to barrels.
Belting intended for driving machinery is built up of canvas which has been thoroughly frictioned with the soft mixed rubber, and is cured by placing it in a kind of press kept by means of steam at a dry heat of about 140° C. Packing for the stuffing boxes of steam engines is similarly prepared from strips of rubber and friotioned canvas, as also are the so-called insertion sheets, in which layers of rubber alternate with canvas or even wire gauze.
The strength of the current may also be regulated by introducing lengths of German silver or iron wire, carbon rod, or other inferior conductors in the path of the current, and a series of such resistances should always be provided close to the tanks.
Large metallic surfaces (especially external surfaces) are sometimes plated by means of a "doctor," which, in its simplest form, is a brush constantly wetted with the electrolyte, with a wire anode buried amid the hairs or bristles; this brush is painted slowly over the surface of the metal to be coated, which must be connected to the negative terminal of the electrical generator.
Others have arranged a means of obtaining high conductivity wire from cathode-copper without fusion, by depositing the metal in the form of a spiral strip on a cylinder, the strip being subsequently drawn down in the usual way; at present, however, the ordinary methods of wire production are found to be cheaper.
p. 16) also worked out, but did not proceed with, a process in which a copper wire whilst receiving a deposit of copper was continuously passed through the drawplate, and thus indefinitely extended in length.
Its breaking strain is very small: a wire 1 o th in.
A wire carrying an electric current is surrounded by a magnetic field, and if the wire is bent into the form of an elongated coil or spiral, a field having certain very useful qualities is generated in the interior.
If a wire of soft iron is substituted for the suspended magnetic needle, either pole of the bar-magnet will attract either end of the wire indifferently.
The wire will in fact become temporarily magnetized by induction, that end of it which is nearest to the pole of the magnet acquiring opposite polarity, and behaving as if it were the pole of a permanent magnet.
In the internal field of a long coil of wire carrying an electric current, the lines of force are, except near the ends, parallel to the axis of the coil, and it is chiefly for this reason that the field due to a coil is particularly well adapted for inductively magnetizing iron and steel.
Again, a steel wire through which an electric current has been passed will be magnetized, but so long as it is free from stress it will give no evidence of magnetization; if, however, the wire is twisted, poles will be developed at the two ends, for reasons which will be explained later.
A wire or rod in this condition is said to be circularly magnetized; it may be regarded as consisting of an indefinite number of elementary ring-magnets, having their axes coincident with the axis of the wire and their planes at right angles to it.
The magnetic field due to a long straight wire in which a current of electricity is flowing is at every point at right angles to the plane passing through it and through the wire; its strength at any point distant r centimetres from the wire is H = 21/r, (2) i being the current in C.G.S.
3 The lines of force are evidently circles concentric with the wire and at right angles to it; their direction is related to that of the current in the same manner as the rotation of a corkscrew is related to its thrust.
The field strength in the interior of a long uniformly wound coil containing n turns of wire and having a length of 1 centimetres is (except near the ends) H = 41rin/l.
In certain cases, as, for instance, in an iron ring wrapped uniformly round with a coil of wire through which a current is passing, the induction is entirely within the metal; there are, consequently, no free poles, and the ring, though magnetized, constitutes a poleless magnet.
In the middle part of a rod which has a length of 400 or 500 diameters the effect of the ends is insensible; but for many experiments the condition of endlessness may be best secured by giving the metal the shape of a ring of uniform section, the magnetic field being produced by an electric current through a coil of wire evenly wound round the ring.
- An electric current i flowing uniformly through a cylindrical wire whose radius is a produces inside the wire a magnetic field of which the lines of force are concentric circles around the axis of the wire.
At a point whose distance from the axis of the wire is r the tangential magnetic force is H = 21r /a 2 (39) it therefore varies directly as the distance from the axis, where it is zero.'
If the wire consists of a ferromagnetic metal, it will become " circularly magnetized by the field, the lines of magnetization being, like the lines of force, concentric circles.
So long as the wire (supposed isotropic) is free from torsional stress, there will be no external evidence of magnetism.
Thus if the magnet is suspended horizontally by a fine wire, which, when the magnetic axis points north and south, is free from torsion, and if 0 is the angle through which the upper end of the wire must be twisted to make the magnet point east and west, then MH = CB, or M = C6/H, where C is the torsional couple for r 0.
A bifilar suspension is sometimes used instead of a single wire.
This extraneous influence may, however, be eliminated by surrounding the rod with a coil of wire carrying a current such as will produce in the interior a magnetic field equal and opposite to the vertical component of the earth's field.
Of the three methods which have been described, the first two are generally the most suitable for determining the moment or the magnetization of a permanent magnet, and the last for studying the changes which occur in the magnetization of a long rod or wire wl?E:n subjected to various external magnetic forces, or, in other words, for determining the relation of I to H.
The tube is wound over its whole length with two separate coils of insulated wire, the one being outside the other.
C is a " compensating coil " consisting of a few turns of wire through which the magnetizing current passes; it serves to neutralize the effect produced upon the magnetometer by the magnetizing coil, and its distance from the magnetometer is so adjusted that when the circuit is closed, no ferromagnetic metal being inside the magnetizing coil, the ti, magnetometer needle undergoes no deflection.
The specimen upon which an experiment is to be made generally consists of a wire having a " dimensional ratio " of at least 300 or goo; its length should be rather less than that of the magnetizing coil, in order that the field Ho, to which it is subjected, may be approximately uniform from end to end.
The wire is supported inside the glass tube A with its upper pole at the same height as the magnetometer needle.
From the former we deduce Ho, and from the latter the corresponding value of I, using the formulae Ho = 47rin/l and I - X s, (d (-- 11)2n7rr 2 i where s is the deflection in scale-divisions, n the distance in scaledivisions between the scale and the mirror, and r the radius of the wire.
When the length of the wire exceeds 400 diameters, or thereabouts, Ho may generally be considered as equivalent to H, 10.
the actual strength of the field as modified by the magnetization of the wire; but if greater accuracy is desired, the value of H, (= NI) may be found by the help of du Bois's table and subtracted from Ho.
The effect of the ends of the wire is, as Ewing remarks, to shear the diagram in the horizontal direction through the angle which the sloping line makes with the vertical.
If the conductor consists of a coil of wire the ends of which are connected with a suitable galvanometer, the integral electromotive force due to a sudden increase or decrease of the induction through the coil displaces in the circuit a quantity of electricity Q=SBns R, where SB is the increment or decrement of induction per square centimetre, s is the area of the coil, n the number of turns of wire, and R the resistance of the circuit.
The sample may have the form of a closed ring, upon which are wound the induction coil and another coil for taking the magnetizing current; or it may consist of a long straight rod or wire which can be slipped into a magnetizing coil such as is used in magnetometric experiments, the induction coil being wound upon the middle of the wire.
In the same circuit is also included the induction coil E, which is used for standardizing the galvanometer; this secondary coil is represented in the diagram by three turns of wire wound over a much longer primary coil.
Fine steel wire 0.257 mm.
Fine iron wire 0.34 mm.
Fine iron wire 0.2475 mm.
Iron wire 0.602 mm.
Iron wire 0.975 mm.
Very soft iron wire.
An experiment by Ewing showed that by the operation of stretching an annealed iron wire beyond the limits of elasticity the permeability under a magnetizing force of about 3 units was reduced by as much as 75%.
The permeability of a soft iron wire, which was tapped while subjected to a very small magnetizing force, rose to the enormous value of about 80,000 (Magnetic Induction, § 85).
A small coil of fine wire, connected in series with a ballistic galvanometer, is placed in the field, with its windings perpendicular to the lines of force, and then suddenly reversed or withdrawn from the field, the integral electromotive force being twice as great in the first case as in the second.
A little instrument, supplied by Hartmann and Braun, contains a short length of fine bismuth wire wound into a flat double spiral, half an inch or thereabouts in diameter, and attached to a long ebonite handle.
If a coil of insulated wire is suspended so that it is in stable equilibrium when its plane is parallel to the direction of a magnetic field, the transmission of a known electric current through the coil will cause it to be deflected through an angle which is a function of the field intensity.
An oblong coil about an inch in length is suspended from each end by thin strips of rolled German silver wire, one of which is connected with a spiral spring for regulating the tension, the other being attached to a torsion-head.
- The most generally convenient arrangement for producing such magnetic fields as are required for experimental purposes is undoubtedly a coil of wire through which an electric current can be caused to flow.
Upon the central neck was wound a coil consisting of one or two layers of very fine wire, which was connected with a ballistic galvanometer for measuring the induction in the iron; outside this coil, and separated from it by a small and accurately determined distance, a second coil was wound, serving to measure the induction in the iron, together with that in a small space surrounding it.
Using an unannealed Swedish iron wire, he found that when H was gradually diminished from 0.04 to 0.00004 C.G.S.
It is remarkable that the phenomena of magnetic viscosity are much more evident in a thick rod than in a thin wire, or even in a large bundle of thin wires.
What actually happens when an iron wire is loaded with various weights is clearly shown in Fig.
The effects of tension upon the behaviour of a nickel wire are of a less simple character.
Knott on magnetic twist, which will be referred to later, led him to form the conclusion that in an iron wire carrying an electric current the magnetic elongation would be increased.
In the case of a wire 0.75 mm.
[[[Stress And Magnetization]] magnetized under very heavy loads, the wire was indeed found to undergo slight contraction.
Taylor Jones showed in 1897 that only a small proportion of the contraction exhibited by a nickel wire when magnetized could be accounted for on Kirchhoff's theory from the observed effects of pulling stress upon magnetization; and in a more extended series of observations Nagaoka and Honda found wide quantitative divergences between the results of experiment and calculation, though in nearly all cases there was agreement as to quality.
Villari in 1868 that the magnetic susceptibility of an iron wire was increased by stretching when the magnetization was below a certain value, but diminished when that value was exceeded; this phenomenon has been termed by Lord Kelvin, who discovered it independently, the " Villari reversal," the value of the magnetization for which stretching by a given load produces no effect being known as the " Villari critical point " for that load.
The following table shows the values of I and H corresponding to the Villari critical point in some of Ewing's experiments: The effects of pulling stress may be observed either when the wire is stretched by a constant load while the magnetizing force is varied, or when the magnetizing force is kept constant while the load is varied.
] being to diminish the magnetization; on the other hand, with very weak fields the maximum may not have been reached with the greatest load that the wire can support without permanent deformation.
When the load on a hardened wire is gradually increased, the maximum value of I is found to correspond with a greater stress than when the load is gradually diminished, this being an effect of hysteresis.
Analogous changes are observed in the residual magnetization which remains after the wire has been subjected to fields of different strength.
Even under so " moderate " a load as 33 kilogrammes per square mm., the induced magnetization of a hard-drawn nickel wire in a field of 60 fell from 386 to 72 units, while the residual was reduced from about 280 to io.
The most interesting of his discoveries, now generally known as the " Wiedemann effect," is the following: If we magnetize longitudinally a straight wire which is fixed at one end and free at the other, and then pass an electric current through the wire (or first pass the current and then magnetize), the free end of the wire will twist in a certain direction depending upon circumstances: if the wire is of iron, and is magnetized (with a moderate force) so that its free end has north polarity, while the current through it passes from the fixed to the free end, then the free end as seen from the fixed end will twist in the direction of the hands of a watch; if either the magnetization or the current is reversed, the direction of the twist will be reversed.
If we twist the free end of a ferromagnetic wire while a current is passing through it, the wire becomes longitudinally magnetized, the direction of the magnetization depending upon circumstances: if the wire is of iron and is twisted so that its free end as seen from the fixed end turns in the direction of the hands of a watch, while 5 Phys.
The wire is subject to two superposed magnetizations, the one longitudinal, the other circular, due to the current traversing the wire; the resultant magnetization is consequently in the direction of a screw or spiral round the wire, which will be right-handed or left-handed according as the relation between the two magnetizations is right-handed or left-handed; the magnetic expansion or contraction of the metal along the spiral lines of magnetization produces the Wiedemann twist.
Now nickel contracts instead of lengthening when it is magnetized, and an experiment by Knott showed, as he expected, that caeteris paribus a nickel wire twists in a sense opposite to that in which iron twists.
Further, although iron lengthens in fields of moderate strength, it contracts in strong ones; and if the wire is stretched, contraction occurs with smaller magnetizing forces than if it is unstretched.
Bidwell 2 accordingly found upon trial that the Wiedemann twist of an iron wire vanished when the magnetizing force reached a certain high value, and was reversed when that value was exceeded; he also found that the vanishing point was reached with lower values of the magnetizing force when the wire was stretched by a weight.
Maxwell has also given an explanation of the converse effect, namely, the production of longitudinal magnetization by twisting a wire when circularly magnetized by a current passing through it.
If a longitudinally magnetized wire is twisted, circular magnetization is developed; this is evidenced by the transient electromotive force induced in the iron, generating a current which will deflect a galvanometer connected with the two ends of the wire.
A wire magnetized longitudinally and circularly becomes twisted.
Twisting a circularly magnetized wire produces longitudinal magnetization.
C. Twisting a longitudinally magnetized wire produces circular magnetization.
The effects of magnetization upon the torsion of a previously twisted wire, which were first noticed by Wiedemann, have been further studied by F.
4 Nagaoka' has described the remarkable influence of combined torsion and 'tension upon the magnetic susceptibility of nickel, and has made the extraordinary observation that, under certain conditions of stress, the magnetization of a nickel wire may have a direction opposite to that of the magnetizing force.
The metal to be tested was prepared in the form of a ring, upon which were wound primary and secondary coils of copper wire insulated with asbestos.
As in Hopkinson's experiments, ring magnets were employed; these were wound with primary and secondary coils of insulated platinum wire, which would bear a much higher temperature than copper without oxidation or fusion.
A third platinum coil, wound non-inductively between the primary and the secondary, served to carry the current by which the ring was heated; a current of 4.6 amperes, with 16 volts across the terminals, was found sufficient to maintain the ring at a temperature of 11 50° C. In the ring itself was embedded a platinum-thermometer wire, from the resistance of which the temperature was determined.
Most of the permeability-temperature curves were more or less convex towards the axis of temperature, and in all the experiments except those with annealed iron and steel wire, the permeability was greatest at the lowest temperature.
Soc., 1900, 67, 208) found that the resistance of a soft iron wire was increased by about 2/700 in a field of 320 C.G.S.
C. Oersted 6 that a magnet placed near a wire carrying an electric current tended to set itself at right angles to the wire, a phenomenon which indicated that the current was surrounded by a magnetic field.
of wire and 1102 telegraph offices.
Among these are flour mills, factories for the cutting of wire nails and making hollow ware from sheet iron, and factories for the manufacture of umbrellas, boots and shoes, &c.
The pipes are assorted into sizes by passing them through graduated openings in a grilled wire frame, and those of good colour are bleached by the fumes of sulphur.
But this ultimatum was rendered invalid by a wire from Lansing, protesting against any settlement without the participation of America.
It is sufficient to look at wire gauze backed by the sky or by a flame, through a piece of blackened cardboard, pierced by a needle and held close to the eye.
Observed through this the structure of some wire gauze just disappeared at a distance from the eye equal to 17 in., the gauze containing 46 meshes to the inch.
On the other hand, a single wire 0.034 in.
He constructed gratings up to 340 periods to the inch by straining fine wire over screws.
the distance from the centre of one wire or line to the centre of the next, and not otherwise upon the thickness of the wire and the magnitude of the interspace.
Fresnel commenced his researches with an examination of the fringes, external and internal, which accompany the shadow of a narrow opaque strip, such as a wire.
The have been identified by Helbig with small spirals of gold wire, such as are found in early Etruscan tombs lying near the head of the skeleton.
(For details see Hughes, Text-book of Coal Mining, pp. 236-272; Hildenbrand, Underground Haulage by Wire Rope.) Rope haulage is widely used in collieries, and sometimes in other mines having large lateral extent and heavy traffic. With the tail-rope system, cars are run in long trains at high speed, curves and branches are easily worked, and gradients may be steep, though undulating gradients are somewhat disadvantageous.
Sinking pumps, designed for use in shafts in process of sinking, are suspended by wire ropes so as to be raised before blasting and promptly lowered again to resume pumping.
Still, if the attacking side enjoyed an advantage in this respect, the possible landingplaces were few in number and were therefore well indicated, there had been ample time to protect them with earthworks and barbed wire, and in any disembarkation in face of resistance the tactical conditions favour the defence.
The various varieties of rolled plate-glass are now produced for some purposes with a reinforcement of wire netting which is embedded in the mass of the glass.
The wire gives the glass great advantages in the event of fracture from a blow or from fire, but owing to the difference in thermal expansion between wire and glass, there is a strong tendency for such " wired glass " to crack spontaneously.
This term of course includes as special cases the qualities of "malleability" (capability of being flattened out under the hammer) and "ductility" (capability of being drawn into wire); but these two special qualities do not always go parallel to each other, for this reason amongst others - that ductility in a higher degree than malleability is determined by the tenacity of a metal.
A bar of zinc, for instance, as obtained by casting, is very brittle; but when heated to 100° or 150° C. it becomes sufficiently plastic to be rolled into the thinnest sheet or to be drawn into wire.
Pure iron, copper, silver and other metals are easily drawn into wire, or rolled into sheet, or flattened under the hammer.
According to Prechtl, the ordinary metals, in regard to the degree of facility or perfection with which they can be hammered flat on the anvil, rolled out into sheet, or drawn into wire, form the following descending series: Hammering.
Drawing into Wire.
To give an idea of what can be done in this way, it may be stated that gold can be beaten out to leaf of the thickness of - j g - mm.; and that platinum, by judicious work, can be drawn into wire 2?o o mm.
Thus, for instance, chemically pure iron in the ingot has the specific gravity 7.844; when it is rolled out into thin sheet, the value falls to 7.6; when drawn into thin wire, to 7.75.
Its hardware industries are important, and embrace iron rolling, the manufacture of fine wire, needles, springs and silver ornaments.
The next step is to remove the harvested crop to the drying-shed; primed leaves are placed at once in shallow baskets or boxes, and when under cover are strung on string or on wire and hung up on laths in the barn.
Trans., 1808, p. I), produced the alkali metals by passing an intense current of electricity from a platinum wire to a platinum dish, through a mass of fused caustic alkali.
This rod was connected with the negative pole of the generator, and was suspended from one arm of a balance-beam, while from the other end of the beam was suspended a vertical hollow iron cylinder, which could be moved into or out of a wire coil or solenoid joined as a shunt across the two carbon rods of the furnace.
Other important manufactures are iron and steel, slaughtering and meat-packing products, boots and shoes, cigars, furniture, men's clothing, hosiery and knit goods, jute and jute goods, linen-thread, malt liquors, brick, cement, barbed wire, wire nails and planing-mill products.
20 a rigid steel wire or gold frames, with fastening-pieces over the ears; single or double eye-glasses, and hand-glasses, or lorgnettes, being varieties of form, according to the circumstances and the wearer's taste.
In the surface of the metal the workman cuts grooves wider at the base than at the top, and then hammers into them gold or silver wire.
It is, in fact, velvet that has passed through all the usual stages of manufacture except the cutting of the thread along each wire and the withdrawal of the wires.
in one variety of this fabric, a slip of gold foil is laid under each wire, and left in position after the wire is withdrawn, the cutting tool being then used with freedom in some parts of the design, so that the gold gleams through the severed thread, producing a rich and suggestive effect.
Machinery, cement, cordage, wire ropes, tobacco, leather, &c. are manufactured.
Bituminous coal, natural gas and oil abound in the vicinity; the river provides excellent water-power; the borough is a manufacturing centre of considerable importance, its products including iron and steel bridges, boilers, steam drills, carriages, saws, files, axes, shovels, wire netting, stoves, glass-ware, scales, chemicals, pottery, cork, decorative tile, bricks and typewriters.
It can therefore be employed, instead of that costly metal, in the construction of incandescent lamps where a wire has to be fused into the glass to establish electric connexion between the inside and the outside of the bulb.
Among the manufactures are brass and copper work, wire for electrical uses, foundry and machine-shop products, locomotives, knit goods, tin cans and canned goods (especially vegetables).
If the electrified tray is touched with the sealing-wax or ebonite rod, it will not be discharged, but if touched with a metal wire, the hand, or a damp thread, it is discharged at once.
this envelope should be of solid metal; a cage made of fine metal wire gauze which permits objects in its interior to be seen will yet be a perfect electrical screen for them.
We can thus easily calculate the capacity of a long thin wire like a telegraph wire far removed from the earth, as follows: Let 2r be the diameter of the wire, 1 its length, and the uniform Capac ity surface electric density..
Then consider a thin annulus thin of the wire of width dx; the charge on it is equal to thin rod.
But the charge is Q = 21rra, and therefore the capacity of the thin wire is given by C =1/2 log e llr (2).
This formula is important in connexion with the capacity of electric cables, which consist of a cylindrical conductor (a wire) enclosed in a conducting sheath.
Kohlrausch called attention to the close analogy between residual charge and the elastic recovery of strained bodies such as twisted wire or glass threads.
It is also extremely ductile; a single grain may be drawn into a wire 500 ft.
in length, and an ounce of gold covering a silver wire is capable of being extended more than 1300 m.
Gold is dissipated by sending a powerful charge of electricity through it when in the form of leaf or thin wire.
Gold wire may be drawn of any quality, but it is usual to add 5 to 9 dwts.
Graham showed that a wire of palladium alloyed with from 24 to 25 parts of gold does not exhibit the remarkable retraction which, in pure palladium, attends its loss of occluded hydrogen.
Among its manufactures are foundry and machine-shop products, flour, silk, waggons, shoes, gloves, furniture, wire cloth and cigars.
passed through to continue the advance; by nightfall the tangle of trenches and wire at the junction were in British hands and the villages of Queant and Pronville had also been wrested from the enemy.
A loop of plati num wire passed under these tubes serves to suspend the vessel from the balance arm.
The other arm is graduated in ten divisions and carries riders - bent pieces of wire of determined weights - and at its extremity a hook from FIG.
The small interval between the adjacent limbs was then measured with a wire micrometer.
10 A screen of wire gauze, placed in front of the segment through which the fainter star is viewed, was, employed by Bessel to equalize the brilliancy of the images under observation.
Thin platinum wire was rendered incandescent by a voltaic current; a small incandescent electric lamp would now be found more satisfactory.
Having selected the most suitable one he directs the axis of the finder to the estimated middle point between the comet and the star, turns the finder-micrometer in position angle until the images of comet and star lie symmetrically between the parallel position wires, and then turns the micrometer screw (which moves the distance-wires symmetrically from the centre in opposite directions) till one wire bisects the comet and the other the star.
The disk 32 operates the wire gauze screens for equalizing the brightness of the two stars under observation.
When heated in air the metal burns if in the form of thin wire, and is superficially oxidized if more compact.
Modern surveying ships no longer make use of hempen lines with enormously heavy sinkers, such as were employed on the " Challenger," but they sound instead with steel piano wire not more than 310 to 215 of an inch in diameter and a detachable lead seldom weighing more than 70 lb.
All deep-sea measurements are subject to uncertainty because the sounding machine merely measures the length of wire which runs out before the lead touches bottom, and this agrees with the depth only when the wire is perpendicular throughout its run.
It is improbable, however, that the smooth and slender wire is much influenced by currents, and the best deep-sea soundings may be taken as accurate to within 5 fathoms.
The arrangements for this purpose vary, of course, with the amount of work to be done with one fixing of the machinery; where it is likely to be used for a considerable time, the drum and brake are solidly constructed, and the ropes of steel or iron wire carefully guided over friction rollers, placed at intervals between the rails to prevent them from chafing and wearing out on the ground.
With proper precautions, however, wire guides are perfectly safe for use at the highest travelling speed.
Flat ropes of steel or iron wire were and are still used to a great extent, but round ones are now generally preferred.
In Belgium and the north of France flat ropes of aloe fibre (Manila hemp or plantain fibre) are in high repute, being considered preferable by many colliery managers to wire, in spite of their great weight.
They found that if liquid acetylene in a steel bottle be heated at one point by a platinum wire raised to a red heat, the whole mass decomposes and gives rise to such tremendous pressures that no cylinder would be able to withstand them.
The use of steel wire for the construction of guns was one of Armstrong's early ideas.
He perceived that to coil many turns of thin wire round an inner barrel was a logical extension of the large hooped method already mentioned, and in conjunction with I.
In the Arctic and Pacific coast provinces, about Lake Superior, in Virginia and North Carolina, as well as in ruder parts of Mexico and South America, metals were cold-hammered into plates, weapons, rods and wire, ground and polished, fashioned into carved blocks of hard, tenacious stone by pressure or blow, overlaid, cold-welded and plated.
The principal manufactures are cotton goods, carpets and wire goods.
The principle resembles that used in wire drawing.
The coin is balanced by the brass counterpoise J on the lefthand hanger and by little weights made of wire attached to the right-hand hanger at K.
Schwabach is the chief seat of the needle manufacture in Bavaria; its other industries include gold and silver wire work, brewing and the making of soap and earthenware.
In this case one terminal of the battery is connected to the earth, and the other terminal is connected through the galvanometer with the copper wire, the insulation of which it is desired to test.
which is connected to one terminal of the insulated battery B, the other terminal being connected to the metallic conductor CC of the wire under test, through a galvanometer G.
To prevent leakage over the surface of the insulating covering of the wire which projects above the surface of the water, it is necessary to employ a " guard wire P, which consists of a piece of fine copper wire, twisted round the extremity of the insulated wire and connected to the battery.
This guard wire prevents any current which leaks over the surface of the insulator from passing through the galvanometer G, and the galvanometer indication is therefore only determined by the amount of current which passes through the insulator, or by its insulation-resistance.
Another illustration is afforded by a long spiral of wire with coils, say 2 in.
A small metal disk was attached to the centre of the membrane and connected to earth by a fine wire.
The pipe was fixed in a horizontal position, and along the top wall ran a platinum wire wetted with sulphuric acid.
When the wire was heated by an electric current a fine line of vapour descended from each drop. The pipe was closed at the centre by a membrane which prevented a through draught, yet permitted the vibrations, as it was at a node.
Subject to a limitation which we shall examine later, the velocity of a longitudinal disturbance along a wire or rod depends only on the material of the rod, and not upon the cross-section.
The velocity of propagation of a torsional disturbance along a wire of circular section may be found by the transfer of momentum method, remembering that we must now replace linear momentum by angular momentum.
Now suppose that the wire or rod is moved from right to left with velocity U.
But at B there is no torsion, and no torsion couple of one part of the wire on the next.
The mass of matter moving through A per second is pwa 2 U, where a is the radius of the wire and p is its density.
The couple due to the twist of a wire of length 1 through 4 is G= 2nira 4 4/l, and we may put 0/l =d0/dx.
For an iron wire Y is about 10 12 /4, so that for a frequency of 500 in a wire fixed at both ends a length about 5 metres is required.
If the wire is stretched across a room and stroked in the middle with a damp cloth the fundamental is easily obtained, and the first harmonic can be brought out by stroking it at a quarter the length from one end.
Substituting in (33) we get U 2 = n/p. (34) If we now keep the wire at rest the disturbance travels along it with velocity U= d (nip), and it depends on the rigidity and density of the wire and not upon its radius.
The torsional vibrations of a wire are excited when it is bowed.
If small paper rings are put on a monochord wire they rotate through these vibrations when the wire is bowed.
Another form of sensitive jet is very easily made by putting a piece of fine wire gauze 2 or 3 in.
The circuit of the electro-magnet is made and broken by the vibration of the fork in different ways - say, by a wire bridge attached to the lower prong which dips into and lifts out of two mercury cups.
The first rush of the assailants carried them up to the wire and other obstacles, but they were for many hours unable to advance a step farther.
Wire entanglements were disposed in repeated lines in front of the defences, but they were not of a strong type.
In suspension bridges the principal members are in tension, and the introduction of iron link chains about the end of the 18th century, and later of wire ropes of still greater tenacity, permitted the construction of road bridges of this type with spans at that time impossible with any other system of construction.
- A suspension bridge consists of two or more chains, constructed of links connected by pins, or of twisted wire strands, or of wires laid parallel.
used in its strongest form, namely hard-drawn wire.
For erection a suspended platform was constructed on eight wire ropes, on which the chains were laid out and connected.
Another wire rope with a travelling carriage took out the links.
Each wire is taken separately across the river and its length adjusted.
Wire cables were used in the erection, by which the members were lifted from barges and assembled, the operations being conducted from the side piers.
Generally, in addition, wire cables are stretched across the span, from which lifting tackle is suspended.
For stiffened suspension bridges with wire cables, if the dip is 310th of the span the limiting span is 2700 to 3600 ft., and if the dip is *th of the span, 3250 to 4250 ft., according to the factor of safety allowed.
The principal industries are tilework, inlaying with silver wire, and the manufacture of thick-soled yellow slippers, much-esteemed flintlocks, and artistic "towels" used as cape and skirt by Moorish country girls.
The rotation of the mercury is detected and measured by means of a small vane of platinum wire immersed in it, the shaft of this vane being connected by an endless screw with a counting mechanism.
The armature carries on its shaft a commutator made of silver slips, and the current is fed into the armature by means of brushes of silver wire.
Its principle is as follows: Suppose there are two pendulum clocks, one having an ordinary pendulum and the other having a pendulum consisting of a fine coil of wire through which a current is passed proportional to the potential difference of the supply mains - in other words, a shunt current.
In proximity to the upper side of the disk is placed a coil of wire having an iron core, which is a shunt coil, the ends of the coil being connected to the terminals of the supply mains.
A common source of trouble is the short circuiting of the shunt coils owing to the shellaced cotton covering of the wire becoming moist.
On account of their regular form they have been used, threaded on wire, for making ornamental baskets.
Like other towns in this populous region, it is an important manufacturing centre, having coal-mines, iron; wire, glass, chemical and oil works, breweries, &c.
Since 1867 it has been connected with Covington by a wire suspension bridge designed by John A.
Abandoning therefore all a priori theoretical assumption, Bashforth set to work to measure experimentally the velocity of shot and the resistance of the air by means of equidistant electric screens furnished with vertical threads or wire, and by a chronograph which measured the instants of time at which the screens were cut by a shot flying nearly horizontally.
In simplest form it consists of a long, straight, fine, uniform wire stretched over a divided scale.
The ends of this wire are connected to one or more secondary cells of constant electromotive force, a variable resistance being interposed so as to regulate the current flowing through the fine wire.
To one end of this fine wire is attached one terminal of a sensitive galvanometer.
Sliding contacts can be moved along the fine wire into any position.
Supposing that the scale under this wire is divided into 2000 parts and that we are in possession of a standard Clark cell, the electromotive force being known at various temperatures, and equal, say, to 1.434 volts at 15° C. The first process is to set the potentiometer.
The slider is placed so as to touch the fine wire at division No.
1434 on the fine wire, and the Clark cell is connected in between the sliding contact and one terminal of the galvanometer, so that its negative pole is connected through the galvanometer with that end of the fine wire to which the negative pole of the working battery is attached.
The resistance in circuit with the fine wire is then altered until the galvanometer shows no deflexion.
We then know that the fall of potential down the 2000 divisions of the fine wire must be exactly 2 volts.
1), and the potentiometer wire itself has a resistance equal to one of these coils.
One terminal of the galvanometer can then be shifted to the junction 6 7 g between any pair of consecutive coils and the slider shifted to any point on the potentiometer wire.
In some cases the potentiometer wire is wholly replaced by a series of coils divided into small subdivisions.
a b, The scale wire.
To prepare the cadmium amalgam, one part of pure cadmium is dissolved in six parts of pure mercury, and the product while warm and fluid is placed in one limb of the cell and warmed, to ensure perfect contact with the platinum wire.
On placing a piece of potash on a platinum plate, connected to the negative of a powerful electric battery, and bringing a platinum wire, connected to the positive of the battery, to the surface of the potassium a vivid action was observed: gas was evolved at the upper surface of the fused globule of potash, whilst at the lower surface, adjacent to the platinum plate, minute metallic globules were formed, some of which immediately inflamed, whilst others merely tarnished.
6 5, p. 3 2 5) obtained the metal by passing melted potash down a clay tube containing iron turnings or wire heated to whiteness, and Caradau (ibid.
The term is generally applied to describe a particular form of electrodynamometer, consisting of a fixed coil of wire and an embracing or neighbouring coil of wire suspended so as to be movable.
Both in the town and neighbourhood there are numerous foundries and works for iron, brass, steel and bronze goods, while other manufactures include wire, needles and pins, fish-hooks, machinery, umbrella-frames, thimbles, bits, furniture, chemicals, coffee-mills, and pinchbeck and britanniametal goods.
wide, and a little shorter than the three others, to protect them from the direct contact of the strong iron wire with which all were firmly bound together.
The word is particularly used of the cord of a bow, and of the stretched cords of gut and wire upon a musical instrument, the vibration of which.
The brass and bronze industries are carried on at Iserlohn and Altena, those of tin and Britannia metal at Ludenscheid; needles are made at Iserlohn and wire at Altena.
is created between the fixed and movable plates, the latter are drawn into a new position which is resisted by the torque of a wire or by the force due to a weight.
This needle is suspended by a fine platinum silver wire, and its normal position is such that the aluminium paddle blades are just outside the quadrantal-shaped plates.
This movement is resisted by the torsional elasticity of the suspending wire, and hence a fixed indicating needle attached to the movable system can be made to indicate directly on a scale, the difference of potential between the terminals of the instrument in volts.
In other types of electrostatic instruments the movable system rotates round a horizontal axis or rests upon knife edges like a scale beam; in others again the movable system is suspended by a wire.
In these instruments the potential difference between two points is measured by the electric current produced in a wire connecting to two points.
In any case of potential difference measurement it is essential not to disturb the potential difference being measured; hence it follows that in electrokinetic voltmeters the wire connecting the two points of which the potential difference is to be measured must be of very high resistance.
In that known as the Cardew voltmeter, a fine platinum-silver wire, having a resistance of about 300 ohms, is stretched in a tube or upon a frame contained in a tube.
The fine wire is fixed to one end of the tube or frame by an insulated support and the other end is attached to a motionmultiplying gear.
As the frame has the same linear expansion as the wire, external changes of the temperature will not affect their relative length, but if the fine wire is heated by the passage of an electric current, its expansion will move the indicating needle over the scale, the motion being multiplied by the gear.
In the Hartmann and Braun form of hot-wire voltmeter, the fine wire is fixed between two supports, and the expansion produced when a current is passed through it causes the wire to sag down, the sag being multiplied by a gear and made to move an indicating needle over a scale.
In this case, the actual working wire, being short, must be placed in series with an additional high resistance.
Hot wire voltmeters, like electrostatic voltmeters, are suitable for use with alternating currents of any frequency as well as with continuous currents, since their indications depend upon the heating power of the current, which is proportional to the square of the current and therefore to the square of the difference of potential between the terminals.
Electromagnetic voltmeters consist of a coil of fine wire connected to the terminals of the instrument, and the current produced in that wire by a difference of potential between the terminals creates a magnetic field proportional at any point to the strength of the current.
constant magnetic field, and in the interspace between the poles is fixed a delicately pivoted coil of wire carried in jewelled bearings.
The movable coil has attached to it an index needle moving over a scale, and a fixed coil of high-resistance wire is included in series with the movable coil between the terminals of the instrument.
In this case a highresistance wire is connected between the points of which the potential difference is required, and from some known fraction of this resistance wires are brought to an electrostatic voltmeter, or to a movable coil electromagnetic voltmeter, according as the voltage to be measured is alternating or continuous.
The high-resistance wire should, moreover, be one having a negligible change of resistance with temperature.
Any form of electrokinetic voltmeter which involves the passage of a current through the wire necessitates the expenditure of energy to maintain this current and therefore involves cost of production.
If the wire has a resistance of 300 ohms and is connected to two points differing in potential by 100 volts, the instrument passes a current of one-third of an ampere and takes up 33 watts in power.
(iii.) The instrument should have no temperature correction; this is a good quality of electrostatic instruments, but in all voltmeters of the electrokinetic type which are wound with copper wire an increase of one degree centigrade in the average temperature of that wire alters the resistance by 0.4%, and therefore to the same extent alters the correctness of the indications.
The weir is opened by joining the needles of each bay by a chain passed through the eyes at the top and a line of wire through the central rings, so that when released at the top by the tilting of the escape bar by the derrick, they float down as a raft, and are caught by a man in a boat, or, when the cur rent is strong, they are 'mopes ?o drawn to the bank by a rope attached to them previously to their release.
Of these the "acoucryptophone" was one of the most elegant - a light box, shaped like an ancient lyre and suspended by a metallic wire from a piano in the room above.
The kaleidophone, intended to present visibly the movements of a sonorous body, consisted of a vibrating wire or rod carrying a silvered bead reflecting a point of light, the motions of which, by persistence of the successive images on the retina, were thus represented in curves of light.
The adjacent Veira or Wire has a population of 60.
2, having a brass wire of about 1 in.
The upper part of this wire is filed flat on one side, for the stem of the hydrometer, with a mark at m, to which it sinks exactly in proof spirits.
in diameter, while the stem consisted of a wire io in.
" B a stem of hardened steel wire.
" FF a stirrup of wire screwed to the globe at C.
to the middle of the wire or stem.
In comparing the densities of different liquids, it is clear that this instrument is precisely equivalent to that of Fahrenheit, and must be employed in the same manner, weights being placed in the top scale only until the hydrometer sinks to the mark on the wire, when the specific gravity of the liquid will be proportional to the weight of the instrument together with the weights in the scale.
Most commonly it is used in the form of wire, with a small bend or loop at the end.
The open-air education was originally proposed by Chavannes of Lausanne, and largely carried out in the canton of Vaud by Roland, who reared his worms on mulberry trees enclosed within " manchons " or cages of wire gauze and canvas.
It is convenient to place the liquid in a short tube., a platinum wire sealed in at the bottom to convey the current reaching to the level of the open end.
If a short length of platinum wire be inserted vertically into a lighted Bunsen burner the luminous line may be used as a slit and viewed directly through a prism.
The time of transit of the sun or star across the vertical wire of the telescope having been observed by means of a chronometer of which the error is known, it is possible to calculate the azimuth of the sun or star, if the latitude and longitude, of the place of observation are given.
Ice, cigars, hats, boots and shoes are manufactured, but the characteristic local industry is the production of "Panama chains," ornaments made of thin gold wire.
Wollaston indeed had formed the expectation that he could make the conducting wire rotate on its own axis, and in April 1821 he came with Sir H.
Faraday was not there at the time, but coming in afterwards he heard the conversation on the expected rotation of the wire.
This led him in the beginning of September to discover the method of producing the continuous rotation of the wire round the magnet, and of the magnet round the wire.
He did not succeed in making the wire or the magnet revolve on its own axis.
Ampere, Wollaston and others, the realization of the continuous rotation of the wire and the magnet round each other was a scientific puzzle requiring no mean ingenuity for its original solution.
For on the one hand the electric current always forms a closed circuit, and on the other the two poles of the magnet have equal but opposite properties, and are inseparably connected, so that whatever tendency there is for one pole to circulate round the current in one direction is opposed by the equal tendency of the other pole to go round the other way, and thus the one pole can neither drag the other round and round the wire nor yet leave it behind.
In December 1824 he had attempted to obtain an electric current by means of a magnet, and on three occasions he had made elaborate but unsuccessful attempts to produce a current in one wire by means of a current in another wire or by a magnet.
Among the products are packed meats, flour, beer, trunks, crackers, candy, paint, ice, paste, cigars, clothing, shoes, mattresses, woven wire beds, furniture and overalls; and there are foundries, iron rolling mills and tanneries.
The other six are connected to each other and to the lowest one by wire cables and pulleys in such a way that when the cable which connects the two lowest tubes is wound in by means of a winch, each of the tubes except the fixed one will rise within the next one through the same distance.
from the lighthouse there was a "fortified zone" of barbed wire and machine-guns.
In 1808 Sir Humphry Davy, fresh from the electrolytic isolation of potassium and sodium, attempted to decompose alumina by heating it with potash in a platinum crucible and submitting the mixture to a current of electricity; in 1809, with a more powerful battery, he raised iron wire to a red heat in contact with alumina, and obtained distinct evidence of the production of an iron-aluminium alloy.
With the increasing price of copper, it is coming into vogue as an electrical conductor for uncovered mains; it is found that an aluminium wire 0.126 in.
in diameter will carry as much current as a copper wire oï¿½ loo in.
When the price of aluminium is less than double the price of copper aluminium is cheaper than copper per unit of electric current conveyed; but when insulation is necessary, the smaller size of the copper wire renders it more economical.
The Fox river furnishes about 10,000 h.p., which is largely utilized for the manufacture of paper (of which Appleton is one of the largest producers in the United States), wood-pulp, sulphite fibre, machinery, wire screens, woollen goods, knit goods, furniture, dyes and flour.
Gardens of large extent should be encircled by an outer boundary, which is often formed by a sunk wall or ha-ha surrounded by an invisible wire fence to exclude ground game, or consists of a hedge with low wire fence on its inner side.
Standards from which galvanized wire is tightly strained from one end to the other are preferable and very convenient.
The process of rooting these runners should be facilitated by fixing them close down to the soil, which is done by small wooden hooked pegs or by stones; hair-pins, short lengths of bent wire, &c., may also be used.
it closely with wire, by taking off a ring of bark, or by " tonguing."
In other cases they are planted in open baskets of wood or wire, using the porous peat and sphagnum compost.
A tight ligature of twine or wire answers the same end.
By crossing the tying material between the wire and the wood, however, and so preventing.
When shreds and nails are used, short thick wire nails and " medicated shreds " are the best; the ordinary cast iron wall nails being much too brittle and difficult to drive into the wall.
It must be remembered that nails spoil a wall sooner or later, whereas a wire trellis is not only much neater, but enables the gardener to tie his trees up much more quickly.
In training greenhouse plants the young branches should be drawn outwards by means of ties fastened to a string or wire FIG.
The training of certain bedding plants over the surface of the soil is done by small pegs of birch wood or bracken, by loops of wire or cheap hair-pins, or sometimes by loops of raffia having the ends fixed in the soil by the aid of the dibble.
A, Tuning wire.
Ff, Tuning wire.
Next let the balls A' and B' be connected together for a moment by a wire N called a neutralizing conductor which is subsequently removed.
The piece K is parallel to G H, and both of them are furnished at their ends with small pieces of flexible wire that they may touch the pins E, F in certain points of their revolution.
From the brass piece M there stands out a pin I, to touch against a small flexible wire or spring which projects C sideways from the rotating plate B when it comes op posite A.
The wire which connects two armature plates for a moment is the neutralizing conductor.
The rotating balls are the carriers, and are connected together for a moment by a wire when in a position to be acted upon inductively by the field plates, thus acquiring charges of opposite sign.
The studs on the armature plate were charged inductively by being connected for a moment by a neutralizing wire as they passed in front of the field plates, and then gave up their charges partly to renew the field charges and partly to collecting combs connected to discharge balls.
Each upright bearing carrying the shafts of the revolving disks also carries a neutralizing conductor or wire ending in a little brush of gilt thread.
The operation of the machine is as follows: Let us suppose that one of the studs on the back plate is positively electrified and one at the opposite end of a diameter is negatively electrified, and that at that moment two corresponding studs on the front plate passing opposite to these back studs are momentarily connected together by the neutralizing wire belonging to the front plate.
The moment, however, a pair of studs on the front plate are charged, they act as field plates to studs on the back plate which are passing at the moment, provided these last are connected by the back neutralizing wire.
The park was presented in 1862 by the widow of Joseph Locke, M.P. The manufacture of iron and steel, and the weaving of linen and other cloth, are the two principal industries; but there are also bleachfields, printfields, dyeworks, sawmills, cornmills and malt-houses; and the manufacture of glass, needles and wire is carried on.
For one kind of meat we could substitute another; wool could be replaced by cotton, silk or fur; were our common silicate glass gone, we could probably perfect and cheapen some other of the transparent solids; but even if the earth could be made to yield any substitute for the forty or fifty million tons of iron which we use each year for rails, wire, machinery, and structural purposes of many kinds, we could not replace either the steel of our cutting tools or the iron of our magnets, the basis of all commercial electricity.
Hence the weakness and the dark-grey fracture of this iron, and hence, by brushing this fracture with a wire brush and so detaching these loosely clinging flakes of graphite, the colour can be changed nearly to the very light-grey of pure iron.
In passing, it may be noted that the cost of the ore itself forms a relatively small part of the cost even of the cruder forms of steel, hardly a quarter of the cost of such simple products as rails, and an insignificant part of the cost of many most important finished objects, such as magnets, cutting tools, springs and wire, for which iron is almost indispensable.
In the Bessemer process, and indeed in most high-temperature processes, to operate on a large scale has, in addition to the usual economies which it offers in other industries, a special one, arising from the fact that from a large hot furnace or hot mass in general a very much smaller proportion of its heat dissipates through radiation and like causes than from a smaller body, just as a thin red-hot wire cools in the air much faster than a thick bar equally hot.
But in addition to the greater cost of steel founding as compared with rolling there are two facts which limit the use of steel castings: (1) they are not so good as rolled products, because the kneading which the metal undergoes in rolling improves its quality, and closes up its cavities; and (2) it would be extremely difficult and in most cases impracticable to cast the metal directly into any of the forms in which the great bulk of the steel of commerce is needed, such as rails, plates, beams, angles, rods, bars, and wire, because the metal would become so cool as to solidify before running far in such thin sections, and because even the short pieces which could thus be made would pucker or warp on account of their aeolotachic contraction.
The rolls thus both draw the piece forward like the pincers of a wire die, and themselves are a die which like a river ever renews or rather maintains its fixed shape and position, though its particles themselves are moving constantly forward with " the piece " which is passing between them.
- Wire undergoing Reduction in the Die.
Pieces of very small cross section, like wire, are more conveniently made by drawing through a die than by rolling, essentially because a single draft reduces the cross section of a wire much more than a single pass between rolls can.
This in turn is because the direct pull of the pincers on the protruding end of the wire is much stronger than the forward-drawing pull due to the friction of the cold rolls on the wire, which is necessarily cold because of its small section.
the summer is propagated by the mosquito (Anopheles claviger) marks a new epoch; the most diverse theories as to its origin had hitherto been propounded, but it is now possible to combat it on a definite plan, by draining the marshes, protecting the houses by fine mosquito-proof wire netting (for Anopheles is not active by day), improving the water supply, &c., while for those who have fever, quinine (now sold cheaply by the state) is a great specific. A great improvement is already apparent; and a law carried in 1903 for the Bonifica dell' Agro Romano compels the proprietors within a radius of some 6 m.
Among Fairfield's manufactures are chemicals, wire and rubber goods.
A recent application of the diamond is for wire drawing; a hole tapering towards the centre is drilled through a diamond, and the metal is drawn through this.
No other tool is so endurable, or gives such uniform thickness of wire.
square sunk into the blue ground; the diamantiferous rock was hoisted by bucket and windlass, and roadways were left across the pit to provide access to the claims. But the roadways soon fell in, and ultimately haulage from the claims could only be provided by means of a vast system of wire ropes extending from a triple staging of windlasses erected round the entire edge of the mine, which had by this time become a huge open pit; the ropes from the upper windlasses extended to the centre, and those from the lower tier to the sides of the pit; covering the whole mass like a gigantic cobweb.
(six truck loads); these are rapidly hoisted to the surface, where their contents are automatically dumped into side-tipping trucks, and these in turn are drawn away in a continual procession by an endless wire rope along the tram lines leading to the vast " distributing floors."
Both methods depend on the observation of the steady distribution of temperature in a bar or wire heated by an electric current.
It has manufactures of wire, leaden pipes and other metal goods, cement, sugar, &c.
They are then spread out thinly on trays or racks made of bamboo, canvas or wire netting, under cover, for some 18 or 30 hours (according to the temporary weather conditions) to wither, after which they are in a soft, flaccid condition ready for rolling.
Various applications of the same system are in use, but the most popular is to place the leaves on trays of wire network in a high temperature for about twenty minutes, after which they are firm and crisp. Up to this point of the manufacture the leaf has been in the stalk, the leaves and bud being unseparated.
In Trenton, also, are manufactured iron, steel and copper wire, rope, cables and rods - the John A.
Roebling's Sons Company has an immense wire and cable manufactory here - iron and steel bridge building materials and other structural work, plumbers' supplies (manufactured by the J.
In its most sensitive form r is a steel wire, the upper end of which passes freely through a small hole in a metal plate.
consists of a weight of 300 kilos suspended by a wire 25 metres in length, the movements of which by means of writing indexes are multiplied 12.5 times.
Attached to the pendulum is a coil of fine wire which moves in the field of a pair of magnets.
Thin wire was hammered out, but there is no ancient instance of drawn wire.
Large tiles, a foot in length, were glazed completely all over, and used to line the walls of rooms; they were retained in place by deep dovetails and ties of copper wire.
Besides having a considerable share in the commerce of the port of New York, Bayonne is an important manufacturing centre; among its manufactures are refined petroleum, refined copper and nickel (not from the ore), refined borax, foundry and machine-shop products, tubular boilers, electric launches and electric motors, chemicals (including ammonia and sulphuric and nitric acids), iron and brass products, wire cables and silk goods.
In miscellaneous metal trades, embracing tinplate goods, wire workers, makers of stoves, grates, ranges and fire-arms, makers of bolts, nuts, rivets, screws and staples, and those occupied in several subsidiary trades, the number of operatives in 1901 amounted to 13,209.
These in Dortmund more particularly embrace steel railway rails, mining plant, wire ropes, machinery, safes and sewing machines.
In 1905 the iron and steel product had increased in value since 1900 44.9%, to $ 8 7,35 2, 7 61; the foundry and machine shop products 25.2%, to $79,9 61, 4 82; and the wire product showed even greater increase, largely because of a difference of classification in the two censuses, the value in 1905 being $14,099,566, as against $2,879,188 in 1900, showing an increase of nearly 390%.
There are also iron bar, hoop and wire works, tool, soap, glass and chemical works, foundries and cotton mills.
Other manufactures are railway cars, casks, cooperage, saw and planing mill products, furniture, wooden ware, windmills, gas-engines, and mattresses and wire beds.
The durability and the extraordinary ductility and pliancy of gold, its power of being subdivided, drawn out or flattened into wire or leaf of almost infinite fineness, have led to its being used for works where great minuteness and delicacy of execution were required; while its beauty and rarity have, for the most part, limited its use to objects of adornment and luxury, as distinct from those of utility.
A pattern was incised with a graver in iron or steel, and then gold wire was beaten into the sunk lines, the whole surface being then smoothed and polished.
Objects that do not require annealing are produced by dozens per minute, and all the movements of feeding and stamping and removal are often automatic. The ductility of metals and alloys is utilized in wire and tube-drawing through dies on long benches.
The quick-lime is then slaked with the requisite quantity of water; the product is passed through a fine-meshed wire sieve and is spread in layers of 2 or 3 in.
(5) The Hargreaves-Bird process avoids certain drawbacks attached to other processes, by employing a wire diaphragm and converting the caustic soda as it issues on the other side of this, by means of carbon dioxide, into a mixture of sodium carbonate and bicarbonate, which separates out in the solid state.
Excluding the Indo European telegraph wire, the whole telegraph system of India forms an imperial charge, administered through a director-general.
Repeated annexations, the spread of education, the appearance of the steam engine and the telegraph wire, all alike revealed a consistent determination to substitute an English for an Indian civilization.
But a floor, however heavy, suspended by three wire ropes and properly balanced over large, well-mounted pulleys, requires an amount of energy to work it which does not exceed that required to operate a platform of moderate dimensions, and there is a freedom, a safety and a facility of working with a complete floor which no partial platform can give.
Barbed wire >>
The body to be tested is placed in a special scale-pan, suspended by a fine wire from the arm of a balance inside an enclosure which can be filled with steam at atmospheric pressure.
The Calorimeter Was Suspended By A Steel Wire, The Torsion Of Which Made The Equilibrium Stable.
The Frictional Generation Of Heat In A Metallic Wire Conveying A Current Can Be Measured In Various Ways, Which Correspond To Slightly Different Methods.
By Ohm'S Law, And By The Definition Of Difference Of Electric Pressure Or Potential, We Obtain The Following Alternative Expressions For The Quantity Of Heat H In Joules Generated In A Time T Seconds By A Current Of C Amperes Flowing In A Wire Of Resistance R Ohms, The Difference Of Potential Between The Ends Of The Wire Being E = Cr Volts: H=Ect=Crt=E Z T/R.
The Resistance R Could Be Deduced From A Knowledge Of The Temperature Of The Calorimeter And The Coefficient Of The Wire.
But In Order To Obtain Trustworthy Results By This Method He Found It Necessary To Employ Very Rapid Stirring (2000 Revolutions Per Minute), And To Insulate The Wire Very Carefully From The Liquid To Prevent Leakage Of The Current.
He Also Made A Special Experiment To Find How Much The Temperature Of The Wire Exceeded That Of The Liquid Under The Conditions Of The Experiment.
The Wire Had A Length Of 760 Cms., And The Potential Difference On Its Terminals Was Nearly 30 Volts.
In The Case Of Water Or Other Liquids It Is Necessary To Employ A Platinum Wire Stretched Along The Tube As Heating Conductor.
The latter are formed of two spirals of wire, sometimes four such spirals being used, whilst there were also brooches in animal forms, one of the latter being found with a bronze sword.
The variation of the horizontal force is obtained by the motion of a magnet which is carried either by a bifilar suspension or by a fairly stiff metal wire or quartz fibre.
The word usage examples above have been gathered from various sources to reflect current and historial usage. They do not represent the opinions of YourDictionary.com.