H. S. Norrie

“ The zinc combines with the chlorine of the solution, liberating free hydrogen and ammonia. The hydrogen appears at the carbon, where it is acted upon by the oxygen of the peroxide of manganese. If too much current is taken from the cell, that is, if the wire or circuit be of too low resistance, the oxidizing action of the peroxide is not rapid enough, and a film of hydrogen, which is a poor conductor, forms over the carbon and increases the resistance of the battery—also setting up what is termed “local action” (actually, a battery opposing a battery) . ”

“ The Electric Light possesses the great advantage over gas, in that it can be turned on or lighted from a distance. The customary means of igniting gas with a match or taper is both dangerous and often inconvenient. The inventive genius of modern times has evolved a means of lighting gas by electricity which is both reliable and easy of application. ”

“ For energizing a gas lighting primary coil, the current must be large, but is only required occasionally, the battery standing idle for long periods. In this case the class called open circuit cells are preferable, as they contain no strong acids and do not deteriorate to any extent when not in use. Of such class is the Leclanche-Samson, Monarch, carbon cylinder, and most so-called dry cells. As the resistance in a conductor [Pg 81] affects the current flow, so it does in a battery cell; the internal resistance of a battery is determined by its size, proximity of the elements, etc. ”

“ If now a coil of insulated wire S be included in the circuit, Fig. 2, upon repeating the make and break of contact, [Pg 3] the sparks will be much increased. This arises from induction, each adjacent turn of wire acting upon its neighbor. To better understand the action of induction, we will consider the following examples: Fig. 3. A is a circuit in which is the battery cell B. C is a second circuit lying close to but well insulated from circuit A. G is a galvanometer in which a magnetized needle swings right or left each time a current is passed through a coil of wire encircling it. ”

“ In general wiring, use weatherproof office wire, or, better still, well-made electric light wire. For ordinary house work No. 16 B. & S. gauge is preferable; smaller wire means higher resistance and less current at burner. For braided office wire, No. 16 runs about 95 feet to the pound, No. 18 about 135 feet to the pound. The cheaper grades of wire without the patent finish or extra insulation are not worth using; sooner or later trouble will ensue, [Pg 37] and once a house is wired, it is no pleasant job to hunt trouble, especially if the wire was put on before the plaster. ”

“ The wire used to connect the burners is generally bare, although an insulated wire is sometimes used. But the electromotive force of a 2-inch spark is so high that it is better to run the wires so they do not come near anything liable to cause a leak. The remarkable tendency of these high-tension currents must be most carefully guarded against; indeed, it is what makes this style of gas lighting so often unsuccessful. A damp wall, gilt wall-paper, a gas pipe hidden in the plaster, will often lead off the current. ”

“ Cells with small zincs and porous cups are of high internal resistance, those with large sheet zincs and big carbon surfaces, of low internal resistance. As the primary coil used in gas lighting is never much over one ohm, a cell of low internal resistance should be selected. But as the wires leading to the burners must be taken into account, a number of cells should be used to produce enough electromotive force to overcome the added resistance. Now battery cells can be arranged in a variety of ways—in series for higher electromotive force, and in multiple—for greater current.
Fig. ”

“ Now when an ordinary pendant or ratchet burner is pulled, it only sends a momentary current through the coil, enough to magnetize the core, but not enough to attract the armature sufficiently long for the bell to ring. But if a short circuit or ground should occur, the armature is held against the contact long enough to cause the bell to ring and give warning. In some cases a constant ringing attachment is added, in which case the bell rings until some one stops it. ”

“ When the chain is fished out, a piece of wire can be attached to the thread and pulled through in turn. In most cases its point of exit at the fixture can be concealed by the rosette, through a hole in which it passes. Take care that the edges of this hole do not cut the insulation. Care must be taken at every step in gas-lighting wiring.
In wiring up a push-button, screw all wires tightly under their respective binding screws, and then cover wherever possible with adhesive tape. ”

“ The lighting armature will buzz violently when touched, whereas the extinguishing one only strikes once when contact is [Pg 30] made. When only one person is working, a pin can be wedged in the push so as to keep the circuit closed.
In setting up these burners care must be taken not to bend contacts or alter adjustments, and absolute precaution is necessary that no wires touch where uninsulated. A cause of trouble is a dirty burner which does not allow the gas to strike the contact spark. ”

“ C the iron core, P the primary coil wires, I the insulating tube between primary P and the secondary coil S. In small coils this may be dispensed with, and a heavy layer of paraffin wax laid over the primary coil. D D are the ends of the secondary, showing sparking taking place between a pair of balls (or between the electrodes of a gas burner) ; R is a stiff spring fastened to the coil base and carrying a soft iron hammer, which is attracted toward the iron core, C, when current passes through the primary coil and magnetizes it. ”

“ A gas burner protrudes from the top of a brass case which encloses the actuating mechanism. This mechanism consists generally of two electro-magnets, the armature of one opening the valve and allowing the gas to flow, at the same time vibrating a platinum-tipped rod against an electrode upon the burner collar. ”

“ The flame from this gas is hotter than that of coal gas, and deposits so much more carbon that a slight modification is necessary in the construction of burners for it. The details can be readily seen on observation of a burner, being simply in the adjustment of the contacts and their operation. It is better, however, to use a larger coil and a stronger battery for gasolene gas lighting than would be needed for coal gas—say, 6 cells of Samson, or large-size New Standard dry battery and a 10-inch coil having about 4 pounds or more of wire on it. ”

“ See that all wires are tightly clamped in terminals, also that their ends are clean. A loose contact is productive of infinite trouble. Examine connections that elements are in proper relation to each other. If in multiple, to produce large current—zincs together and carbons together. If in series, for high electromotive force—zinc to carbon, throughout battery.
Zincs.—See that the zincs are clean; if crystals form, either reduce strength of solution with water, or scrape zincs clean, and watch if repeated. Examine screw which holds wire ”

“ C is current in amperes, E electromotive force in volts, and R resistance in ohms.
Thus a wire with a resistance of 50 ohms would pass 2 amperes with an electromotive force of 100 volts. To find resistance when other two factors are known, the formula is
R = E/C.
In selecting a battery for work, regard must be made to the current required, and its period of flow. ”

“ Fig. 9 shows a form of pendant burner which has no platinum contact, but has a broad lug on the insulated collar which is scraped against by the spiral spring when the arm is pulled down. It will be seen that the lug is not held by an insulated collar on the burner top, but is on the extension of an arm attached to the burner pillar by a large screw and insulating washers. The circuit wire goes under the smaller screw seen on the lower part [Pg 10] of the contact arm, this forming a strong and neat form of attachment. ”

“ Fig. 24 is the detail of the wiring for the cellar automatic burner A, from the push P, and is so clearly shown as not to require further explanation.
The secret of success in gas-lighting work is careful wiring. The platinum tip of the vibrating rod is often bent, either by accidental blow or by the continual hammering against the tip on the collar. This often causes an open circuit when the lighting armature refuses to buzz. Again, soot will form, causing weak action owing to imperfect contact. ”

“ The best arrangement is depicted in Fig. 15, which has a pilot-tube burner as well as the two main tips. On turning the key, gas is admitted to both main and pilot burners, but [Pg 17] the electrode in breaking contact only ignites the gas at pilot burner, which, in its turn, [Pg 18] acts as a lighter for the main burner. Turning the main burner out, the pilot light can be left burning if desired, giving a small light, it being not feasible to turn down the main burner owing to the before-mentioned carbonization. ”

“ This wheel is mounted on the stem of a valve which opens or shuts according to the point of rotation, and thus shuts off or admits the gas to flow up to the burner. One pull of the arm turns the gas on; at the same time the wipe spring touches the contact on burner collar, and the gas lights. A second pull and the wheel, rotating, turns off the gas. [Pg 12] In all burners of this class a spring is provided to carry the arm up and back into its original position ready for another pull. Some burners do not make contact when the arm flies back, thus saving battery current. ”

“ As the wires must be somewhat loose to allow of the connections being made at the back of the push-button at the wall, they will have to be carefully pushed into the hole, and if they are not tightly held by screws, trouble will result. It is a good plan, when using fine enough wire, to make a sort of eye at the end of the wire and pass the screw through this, instead of merely giving the wire end a turn around the screw and then driving the screw home. ”

“ A touch of solder will prevent trouble from oxidation, after the [Pg 40] adhesive tape has been wrapped on. Attention to details like these will often ensure the satisfactory working of the job.
A handy tool for gas-lighting wiring is shown in Fig. 25. One end is bored out to fit the small nuts on the ratchet and pendant burners, and the other is filed flat for use as a screw-driver.
Fig. 25.
A case may arise where there is electric light on the same chandelier as the gas lights, and that an insulating bushing has been screwed in between the fixture and the pipe. ”

“ It is customary to allow sixteen burners to one inch of spark, in which case the spark gaps are adjusted about one-sixteenth of an inch apart. A coil giving a 2-inch spark would operate 32 burners, but actually it would be found preferable to omit a few, so as to make allowance for any slight leak. A spark of over 2 inches is hard to handle, although often used; it is better to make up a number of circuits of, say, 30 burners each, and operate them alternately by a suitable switch. ”

“ The wire from the secondary of the coil is run to the switch-handle, H, great care being taken that it does not pass near to the circuit wires, or contact points. Revolving the switch-handle connects the secondary wire to each circuit in turn. It will be noticed that, unlike a battery switch, this one has a large base, long switch-arm, contact points situated far apart, and every precaution taken to control the passage of the high-tension current. The base should always be of rubber or glass. Shellacked-wood, or such substitutes, are productive of trouble.
Fig. ”

“ Take a long piece of wire and fasten one end to a ground pipe. Then touch the other end to the circuit wire in the cellar as far as you can go, baring the insulation in spots, but carefully re-insulating it again. If there is no break in the cellar, the bell will ring loudly at each contact. Next, proceed to the next floor and repeat the operation, gradually working away from the battery. As soon as you pass the break, the bell will fail to respond. Two persons here are better than one, as it may be necessary to go quite a distance from the bell before finding the trouble.
Fig. ”

“ In wiring new wooden buildings do not draw wires too tight; the wood may expand and either break wire or cause a weakening of the insulation. In wiring before the plaster is put on, always leave a good length free, so it will not be covered up by the plasterers.
The wire used on the gas fixture is of a special kind, being made for the purpose. It is made in two sizes, No. 22 and No. 24 B. & S. gauge, and with three windings of cotton, three outer layers of cotton and one of silk, or three windings of cotton which is soaked in fireproof preparation, and then wound with silk. ”

“ When the cell is in working condition, the level of the solution will be found to have receded, owing to absorption by the porous cup. To prevent the creeping of sal ammoniac up the neck of jar and on to the terminals of the cell, a layer of paraffin is applied to neck of jar and porous cup. Should this need renewing, vaseline can be used, or any heavy grease, care being taken that it does not get on electrodes or where the wires are to be fastened. When the cell refuses to work, throw out old solution, wash porous cup, jar and zinc in warm water, and replace with new solution. ”

“ Fig. 50 represents the series arrangement; here the zinc of one cell is connected to the carbon of the next; this adds the electromotive [Pg 82] forces together and thus gives greater ability to overcome resistance, but it also adds together the resistance of each cell. Thus 4 cells, each 2 volts and of one-half ohm internal resistance, would, in series, have an E. M. F. of 8 volts and an internal resistance of 2 ohms, current 4 amperes. Fig. 51 shows four cells in multiple, the zinc of each cell and the carbons of each cell are connected. ”