Hence, when the coil at one fixed station was in action it generated high frequency alternating currents, which were propagated across the air gap between the ordinary telegraph wires and the metallic surfaces attached to one secondary terminal of the induction coil, and conveyed along the ordinary telegraph wires between station and moving train.
He inserts in the primary circuit of the alternating FIG.
The two travelers killed the time picking over a bland lunch and alternating long walks with longer periods of sitting on hard seats, re-reading a discarded newspaper.
If the current is interrupted or alternating, and if a telephone receiver has its terminals connected to a separate metallic circuit joined by earth plates at two other places to the earth, not on the same equipotential surface of the first circuit, sounds will be heard in the telephone due to a current passing through it.
These spark balls are connected either to the secondary circuit of an induction coil I, or to that of an alternating current transformer having a secondary voltage of 20,000 to 100,000 volts.
In order to produce electric oscillations in the system, the first or alternating current transformer must charge the condenser connected to its secondary terminals, but must not produce a permanent electric arc between the balls.
The impedance of the primary or alternator circuit is so adjusted that when both the chokers are in circuit the current flowing is not sufficient to charge the condensers; but when one choker is short-circuited the impedance is reduced so that the condenser is charged, but the alternating arc is not formed.
Adjust the frequency so that it has the value of the normal time period of the circuit formed of the condenser and transformer secondary circuit, and thus it is possible to obtain condenser oscillatory discharges free from any admixture with alternating current arc. In this manner the condenser discharge can be started or stopped at pleasure, and long and short discharges made in accordance with the signals of the Morse FIG.
The electric waves coming through space from the sending station strike against the receiving antenna and set up in it high frequency alternating electromotive forces.
The conditions permit of the circulation of the alternating currents of low periodicity, which are used for operating the bells, but in respect of the battery the circuit is open until the subscriber lifts the receiver, when the hook switch, thus released, joins the transmitter with one winding of an induction coil in series across the circuit.
In another party line system a harmonic principle is employed: the ringing machines deliver alternating currents of four frequencies, while each bell is constructed to operate at a particular frequency only.
In the biserial type the polyps on the two sides of the stem have primitively an alternating, zigzag arrangement; but, by a process of differential growth, quickened in the 1st, 3rd, 5th, &c., members of the stem, and retarded in the 2nd, 4th, 6th, &c., members, the polyps may assume secondarily positions opposite to one another on the two sides of the stem.
Amphogona, hermaphrodite, with male and female gonads on alternating radial canals.
The mystic erratic temperament of Otto, alternating between the most magnificent schemes of empire and the lowest depths of self-debasement, was not conducive to the welfare of his dominions, and during his reign the conditions of Germany deteriorated.
Periderm; c, cortex; ph, phlocni with alternating strands of fibres, sieve-tubes and parenchyma; ~r.r, principal ray; Sr., subordinate rays; ca, cambium.
Here we find open plant associations of Haifa or Esparto Grass (Stipa lenacissima) alternating with steppes of Chih (Artemisia herba-alba); and each plant association extends for several scores of miles.
The book of Judges with its " monotonous tempo - religious declension, oppression, repentance, peace," to which Wellhausen 4 refers as its ever-recurring cycle, makes us familiar with these alternating phases of action and reaction.
The coast-line consists of a succession of great promontories alternating with deep inlets.
The wings in nearly all species have a dappled or speckled appearance, owing to the occurrence of blotches on the front margin and to the arrangement of the scales covering the veins in alternating light and dark patches (Austen).
Although many different rotations of crops are practised, they may for the most part be considered as little more than local adaptations of the system of alternating root-crops and leguminous crops with cereal crops, as exemplified in the old four-course rotation - roots, barley, clover, wheat.
Its subject, which is of high historical value as a record of costume, represents the translation of the body of St Mark, and gives us a view of the west façade of the church as it was at the beginning of the 13th century before the addition of the ogee gables, with alternating crockets and statues, and the intermediate pinnacled canopies placed between the five great arches of the upper storey.
The genital products develop in intermediate spaces similarly limited by these dissepiments and alternating with the digestive caeca.
They are metamerically placed, and belong to the same metamere as the digestive caeca, thus alternating with the generative sacs.
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.
Thermal ammeters recommend themselves for the following reasons: (I) the same instrument can be used for continuous currents and for alternating currents of low frequency; (2) there is no temperature correction; (3) if used with alternating currents no correction is necessary for frequency, unless that frequency is very high.
In certain forms, hot-wire instruments are well adapted for the measurement of very small alternating currents.
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.
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.
The above-described gravity type can be employed with certain restrictions for the measurement of alternating currents.
They are constructed for the measurement not only of continuousor unvarying butalsoof alternating currents.
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.
This immense tract of low land, though in some, parts covered with barren wastes of sand, alternating with marshes, presents in general a very rich and productive soil.
From the South Head of Port Jackson to the North Head of Botany Bay; it consists of bold cliffs alternating with beautiful beaches, of which some are connected with the city by tramway, and form favourite places of resort.
It is the ritual of a magician, imbedded in which, and alternating with magic formulae and other occult matter, are a number of invocations and prayers which Dieterich reconstructs as a liturgy in use by the clergy of Mithras between A.D.
Four kings named Battus, alternating with four named Arcesilaus, ruled in Cyrene till the fall of the dynasty about 450 B.C.
Supposing Ewing's hypothesis to be correct, it is clear that if the magnetization of a piece of iron were reversed by a strong rotating field instead of by a field alternating through zero, the loss of energy by hysteresis should be little or nothing, for the molecules would rotate with the field and no unstable movements would be possible.'
With small magnetizing forces the hysteresis was indeed somewhat larger than that obtained in an alternating field, probably on account of the molecular changes being forced to take place in one direction only; but at an induction of about 16,00o units in soft iron and 15,000 in hard steel the hysteresis reached a maximum and afterwards rapidly diminished.
9) from F to D, while at the same time the commutator K is rapidly worked, a series of alternating currents of gradually diminishing strength being thus caused to pass through the magnetizing coil.
The second has a very small area, showing that the work done in reversing the magnetization is small; the metal is therefore adapted for use in alternating current trans formers.
31 have felsitic bands alternating with others which are purely glassy.
Plains alternating with forests occupy the northern zone of the department, while the central and western regions form an undulating and well-watered plateau.
Along the west frontier there appear broad and strongly marked zones of Cretaceous limestone, alternating with Jurassic and Triassic, joined by a strip of Palaeozoic formations running from the north-west corner of Bosnia.