Lewis Howard Latimer

“ If the electric current can be forced through a substance that is a poor conductor, it will create a degree of heat in that substance, which will be greater or less according to the quantity of electricity forced through it. ”

“ Arrangements are often provided by which lamps may be turned on in the hall at the front door, and extinguished from the top of the stairs, thus allowing one to have a light before them in whatever part of the house they may choose to go. This is a matter of economy as well as convenience, for it allows of lamps being lit only when and where needed, enabling occupants to use light only in the rooms occupied, while the rest of the house remains in darkness that may be dissipated in an instant at the will of any individual occupant. ”

“ That the operations just described should be intelligently and carefully performed, is of the greatest importance, as each lamp when burning represents a given amount of coal being consumed at the station; and as the light is sold at a predetermined and stated price, just as gas is, it is necessary, in order to have the electric light company's books balance in favor of the proper parties, that no coal should be burned unless the light is in actual use. ”

“ We have endeavored in the preceding pages to state the fact clearly that in the Edison three-wire system of incandescent electric lighting the pressure upon the wires is kept constant. A constant pressure implies a constant current, to measure which the Edison meter has been invented. ”

“ If we substitute for the needle a loop of copper wire we shall, by the motion before described, induce in the copper wire a current of electricity, and that without actual contact between the magnet and the wire. ”

“ A glance at the volt meter shows us that we have a pressure greater or less than 100, which is the pressure we require; and by operating the resistance boxes connected with the fields of the dynamos, we secure the proper pressure, and the current being proportional to the pressure divided by the resistance of the lamps in circuit will take care of itself. ”

“ This cut-out is to provide against a larger amount of current than is necessary for the number of lamps to be used entering the house. The meter is also proportioned in size to the number of lamps employed. After passing through the meter, the wires are led to an elevator shaft, hallway, or suitable space provided in the walls for this purpose, as nearly central as may be, and are carried up to the topmost floor to be lighted. On each floor the wires pass through what is known as a pocket, which is generally a boxed-up space provided with a door for easy access to the enclosure. ”

“ If the shaft which supports the loop is rapidly revolved; a current of electricity will be set up in the wire loop by bridging over the space at the ends of the wire between the metal plates with a piece of metal or another loop of copper wire; copper always being used to conduct electricity where it can be, for the reason that it is the best practical conductor of electricity. ”

“ Although electricity, like the air around us, seems very impalpable, appealing to so few of the senses, it is yet capable of being measured, for in order to run the lamps economically, we must give each of them only its due measure of the electric current passing over the wires. ”

“ A Discussion of the best Methods of Treatment of the Sewage of Farm-Houses, Isolated Country Houses, Suburban Dwellings, Houses in Villages and Smaller Towns, and of Larger Institutions, such as Hospitals, Asylums, Hotels, Prisons, Colleges, etc., and of the Modes of Removal and Disposal of Garbage, Ashes, and other Solid House Refuse. ”

“ The end of the brass-steel strip, opposite the screw on the lamp socket, is provided with a contact-point which will rest against the end of the screw under proper conditions; that is, when the temperature in the meter falls below a certain point, the brass on the brass-steel strip, contracting more than the steel, will cause the strip to curve, thus bringing the contact piece on its end against the lamp base screw, and, completing the circuit through the lamp, cause it to glow and disseminate the necessary heat. ”

“ In order, however, that the lamps farthest removed from the generator shall have as much current as those nearest to it, the main conductor must of necessity be so large as to present practically no resistance to the passage of the current; for this reason the two-wire system cannot well be used, under conditions requiring the current to be led a long distance to the point where the lights are to be used, as the cost of the large copper conducting mains becomes so great as to seriously interfere with the economical introduction of the system upon a commercial basis. ”

“ In the practical machine used in electric lighting, the core of the armature is made of thin discs of soft sheet iron; these discs are prevented from touching the shaft by the interposition of insulating material, and have insulating material, arranged between them so as to prevent their touching each other, they are however so rigidly secured to the shaft as to be in no danger of becoming loose when the shaft is rapidly rotated. Fig. 5 shows a complete armature, with commutator attached ready to be placed in position in the generator. ”

“ The various devices once placed are likely to last under ordinary usage as long as the householder will probably live to enjoy them; the only exception to this general statement being the lamp itself which, with the proper current for which it is constructed, is guaranteed to last one thousand hours. ”

“ The author's suggestions on fire prevention and fire protection, although written chiefly with reference to hospitals, lunatic asylums and orphans' homes, are equally applicable to hotels, warehouses, factories, mills, schools, churches, dwelling-houses and public buildings of all kinds. ”

“ Should you hold a horseshoe-magnet a slight distance above a long bar of iron, and then move it forward parallel thereto, you would find that it offered resistance to being moved thus, and that you would be forced to put forth some strength, both to keep it in motion as well as to prevent it being drawn down into contact with the iron ”

“ To make this clearer, we will say that two dynamos are started late in the afternoon a little before the time when lighting generally commences. If no lights are turned on there will be no current generated, because we shall have what is termed an open circuit; that is, there will be no connection between the outgoing and incoming, or what is known as the positive and negative wires, as there is when lamps are in circuit. ”

“ In addition to the large number of advantages possessed by the electric light over all other forms of artificial illumination, it may be said to be far in advance of all others in the readiness with which it may be adapted to all forms of decoration. ”

“ In the first place we must have a large number of these wire loops, and as the wire is soft and easily bent, we must wind it about a core so as to hold it rigidly in place, as it has to be revolved very rapidly. Again, the ends of each wire loop must be brought out and attached to plates or blocks of metal, arranged upon some kind of non-conducting substance at one end of the shaft upon which the whole will turn. ”

“ The couple to be cut out of circuit, have their field-resistance boxes manipulated until they are generating only enough current to keep their pressure up to the proper point to prevent the main current from turning them into motors, when they are thrown out of circuit and the engine driving them is stopped; the other dynamos having meanwhile been so regulated as to divide the total load between them, and this operation is repeated as day draws on, until the entire station is at rest. ”

“ Edison is the fortunate possessor of that rare combination of faculties, superior inventive ability, supplemented by unusual business qualifications and, to his intimates, the fact that he has invented a device is a sufficient guarantee of its commercial utility. ”

“ Although the dynamos about to be turned on may be running at full speed, and ready as soon as thrown into circuit, by what are known as switches, to generate a current of the proper pressure, they need not necessarily be prepared to generate a large amount of current, for the reason that the field-resistance boxes may be so arranged as to allow only a very small amount of the current generated to pass around the fields ”

“ Electric Lighting by Incandescence, had barely got beyond the stage of a laboratory experiment, and the possibility of lighting large districts from a central station, as successfully as with gas, was doubted by men who now stand high in electrical circles. ”

“ The small wires before mentioned as passing from the clips above the bottles to the lower space of the meter box lead the current to the zinc plates in such a manner that it must pass from one plate to the other through the zinc solution. In doing this the current detaches particles of zinc from one of the plates and transfers them to the other, thus decreasing the weight of the first plate. One ampere, acting for one hour, will deposit a known amount of zinc upon the negative plate in the bottle ”

“ While the copper and platinum wires readily conduct the current, the carbon filament offers a great deal of resistance to its passage, and for this reason becomes very hot, in fact is raised to white heat or incandescence, which gives its name to the lamp. ”

“ As the current is generated, it flows toward the pieces of metal arranged on the end of the shaft, and from them into what are called brushes, which are flat pieces of metal that rest against those arranged on the end of the shaft so as to have intimate contact with them without retarding their rotation. ”

“ The globes may be of all colors, and the best talent of the civilized world has been levied upon the production of beautifully designed fixtures to receive them, as well as globes, shades, and reflectors to modify the lights and enhance the beauties of its effects. ”

“ Should the current become too great for its carrying capacity, the alloy would melt and fall down upon the non-conducting base upon which the several portions of the switch are mounted, thus breaking the circuit and cutting off the current until suitable provision be made for its control, when another safety-catch is substituted for the melted one, and all is ready for continued operation. When wires are led into houses, a different form of safety-catch is used. ”

“ Having generated sufficient steam for our purpose we open the valves and let it enter the cylinder of the engine, where its energy is transmuted into the rotations of the fly-wheel and these rotations are in turn transmitted—through the belt connecting the fly-wheel to the pulley on the armature shaft,—to the armature of the generator. ”