In the earlier forms of instrument the record was made by embossing lines on a ribbon of paper by means of a sharp style fixed to one end of a lever, which carried at the other end the armature of an electromagnet.
The armature consists of a bony case, partly composed of solid buckler-like plates, and partly of movable transverse bands, the latter differing in number with the species, and giving to the body a considerable degree of flexibility.
Operators who used the recorder soon learned to read the message by the click of the armature against its stop, and as this left the hands and eyes free to write, reading by sound was usually preferred.
Prominent, unjointed cerci, male with genital armature on second abdominal segment.
The action of the machine is as follows: Suppose one paper armature to be charged positively, it acts by induction on the right hand comb, causing negative electricity to issue from the comb points upon the glass revolving disk; at the same time the positive electricity passes through the closed discharge circuit to the left comb and issues from its teeth upon the part of the glass disk at the opposite end of the diameter.
The charges thus deposited on the glass disk are carried round so that the upper half is electrified negatively on both sides and the lower half positively on both sides, the sign of the electrification being reversed as the disk passes between the combs and the armature by discharges issuing from them respectively.
This armature plate revolved in front of a field plate carrying two pieces of tin-foil backed up by larger pieces of varnished paper.
When one of a series of keys (each corresponding to a letter) arranged round a pointer is depressed, the motion of the pointer, which is geared to the shuttle armature, is arrested on coming opposite that particular key, and the transmission of the currents to line is stopped, though the armature itself can continue to rotate.
An axle carrying four cams is normally at rest, but it is thrown into gear with the mechanism when the armature rises, makes one complete revolution, and comes to rest ready for the next signal.
In its revolution one of its cams engages with the correcting wheel attached to the type-wheel in order to ensure that the latter is in the correct position for printing a complete letter; the second cam lifts the paper against the type-wheel and prints the letter; the third moves forward the paper tape one space to be ready for the printing of the next letter; and the last cam replaces the armature on the cores of the electromagnet.
This hammer is arranged so that when the armature vibrates it gives little blows to the underside of the tube and shakes up the filings.
He proposed to make the armature partake of the vibrations of the atmosphere either by converting it into a suitable vibrator or by controlling its vibrations by a stretched membrane of parchment armature had the form of a hinged lever one end, which pressed against the centre.
The experiments with this form were not successful, and, with the view of making the moving parts as light as possible, he substituted for the comparatively heavy lever armature a small piece of clock spring, about the size of a sixpence, glued to the centre of the diaphragm.
The morphology of the abdomen, ovipositor and genital armature is dealt with by K.
In most of the systems that have been proposed this result is attained by electrical regulation; in one, however, a mechanical method is adopted, the dynamo being so' hung that it allows the driving belt to slip when the speed of the axle exceeds a certain limit, the armature thus being rotated at an approximately constant speed.
14) and the genital armature of the male.
The genital armature of the male is formed to a considerable extent by modifications of the segments themselves.
The development of the armature has been little studied, and the question whether there may be present gonapophyses homologous with those of the female is open.
- The armature from the proboscis of Drepanophorus.
They are cylindrical worm-like animals, with a median anterior mouth quite devoid of any armature or tentacles.
The mouth, which is quite devoid of armature, leads imperceptibly into a short and dorsally directed oesophagus.
The length and armature of the pincers and the presence or absence of wings are perhaps the most important features used by systematists in distinguishing the various kinds.
As all these animals are killed by the poison of the snake before they are swallowed, and as their muscles are perfectly relaxed, their armature is harmless to the snake, which begins to swallow its prey from the head, and depresses the spines as deglutition proceeds.
With regard to the degree in which this armature is developed, not only do the species differ from each other, but almost every species shows an extraordinary amount of variation.
For male genital armature S.
The torque acting on the armature of an electric motor is necessarily accompanied by an equal and opposite torque acting on the FIG.
In one the exciting armature is rotated, producing the working voltage of 250, 500 or loon volts.
One of these coils is in series with the armature circuit and with the insulation or high resistance to be measured.
When the armature is rotated, these two coils endeavour to place themselves in certain directions in the field so as to be perforated by the greatest magnetic flux.
These have a speed reduction from armature shaft to bridge column of 1500 to I, through four intermediate spur gears and a worm gear.
The mass of mercury is thus set in motion owing to the tendency of a conductor conveying an electric current to move transversely across lines of magnetic force; it becomes in fact the armature of a simple form of dynamo, and rotates with a speed which increases with the strength of the current.
It takes the form of a small dynamo having an armature and field magnets without any iron core.
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.
The current to be measured passes through the fixed field-coils, whilst through the armature passes a shunt current obtained by connecting the brushes across the supply mains through a constant resistance.
The driving force is balanced against a retarding force produced by the rotation of a copper disk fixed on the armature shaft, which rotates between the poles of a permanent magnet.
Hence when a current is passed through the meter, the armature rotates and increases its speed until the driving force is balanced against the retarding force due to the eddy currents in the copper brake disk.
In these circumstances the number of rotations made by the armature in a given time is proportional to the product of the strength of the current flowing through the armature and that flowing through the field-coils, the former being the current to be measured.
This last is geared to the shaft of the armature by an endless screw, and the number of revolutions of the armature is reckoned by the counting-dials, which are ' See Electrician, 41, 112, and Journ.
He has applied the theory with especial ingenuity to the interpretation of the circular bony plates in the carapace of the aberrant leather-back sea-turtles (Sphargidae) by prefacing an initial land phase, in which the typical armature of land tortoises was acquired, a first marine or pelagic phase, in which this armature was lost, a third littoral or seashore phase, in which a new polygonal armature was acquired, and a fourth resumed or secondary marine phase, in which this polygonal armature began to degenerate.
The tenth abdominal segment carries strong, unjointed cerci, while the presence of reproductive armature on the second abdominal segment of the male is a character found in no other order of the Hexapoda.
There is no armature, and no glands, and the whole tract can only be divided into an oesophagus and an intestine.
The wire which connects two armature plates for a moment is the neutralizing conductor.
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.
Circuit-closing apparatus called a relay, which is practi cally an electromagnetic key which has its lever attached to the armature of the magnet and which can be worked by a very weak current.
When a current passes through R the armature A is attracted and the local circuit is closed through the armature at b.
In the form of relay indicated in the figure the armature is held against the stop a by a spring S.
Now if the values of the rheostat and condenser are adjusted so as to make the rise and fall of the outgoing current through both windings of the relay exactly equal, then no effect is produced on the armature of the relay, as the two currents neutralize each other's magnetizing effect.
The result is that the armature of the relay is attracted, and currents are sent through the sounder from the local battery, producing the signals from the distant station.
For the dot the armature is deflected by the first current, the ink-wheel being brought into contact with the paper and after a short interval pulled back by the reverse current.
The armature acts on an inking disk on the principle described above, save only that the disk is supplied with ink from a groove in a second wheel, on which it rolls: the grooved wheel is kept turning with one edge in contact with ink in an ink-well.
The armature of the electromagnet is normally attracted by the effect of the permanent magnet, but it is furnished with two antagonistic springs tending to throw it upwards.
The armature is immersed in a shallow vessel filled with mercury, which is insulated from the vessel and the armature, except at the ends of the copper strips.
It is sluggish in its movements, and so harmless that its armature and (to a casual observer) repulsive appearance are its sole means of defence.