MR. HARBISON-How long does it take a man to make a change from one candle to another on the lamp-post? CAPT. DRESSER-The change from one to the other is made by the mere turning of a switch. Each one of these candles, as Mr. Jablochkoff told me, cost about 65 centimes, which is about 13 cents. I see, in a proposition that he made to illuminate certain buildings, he estimates the cost of these candles at 55 centimes, which would be about 11 cents. In the report which was published in the last number of the Gas-Light Journal, upon this matter, I averaged the cost at 12 cents. MR. CARTWRIGHT-How do they arrange the controlling power in lighting a long street, or a long row of lamps? CAPT. DRESSER-They put the steam engines in the cellars of buildings, and their other machines in the same place. Wires are run from the machines to the lamps. MR. LITTLEHALES-What is the greatest distance that the candles may be placed from the power? CAPT. DRESSER-They claim that they can carry it about five or six hundred yards. You will find, however, that when they are making experiments in their laboratories, and even at the Exposition, that they prefer to use about two hundred feet of wire-that is, from their machines to their lamps-because it takes a smaller wire, and is more easily handled. MR. CARTWRIGHT-Do they have a return wire? CAPT. DRESSER-They were all, apparently, covered wires. MR. CARTWRIGHT-How far apart are these candles lighted, generally speaking? CAPT. DRESSER—On an average, one of these electric candles replaces about ten gas burners. I have just received, since this Association has been in session, a report made by Mr. Hunt, who is the engineer of the Birmingham Corporation Gas Works, and who was in Paris at the same time I was. He has kindly forwarded me a copy of his report, and, if you would like to hear what it is, I will read it. MR. HARBISON-I move that it be printed as a part the of proceedings. Carried. Capt. Dresser-Mr. Hunt is a man of a great deal of intelligence. He is a thorough gas maker; he is, at the same time, I believe, a perfectly fair-minded man, and is willing to find out everything he can in favor of the electric light. MR. HARBISON-The reason I suggested that the report be printed with our proceedings is, that it is very possible that there may be those who, after hearing this interesting report read, will want to subscribe to the Journal, in order to get the report. CAPT. DRESSER-I think, after hearing this report, if a man is mean enough not to subscribe to the Journal, we had better let him go. [Laughter.] CAPT. DRESSER then read the report of Mr. Hunt, as follows: CORPORATION OF BIRMINGHAM-GAS DEPARTMENT. Report of Mr. Hunt on Electric Light. I have to report that, agreeably with instructions received through the Secretary, I endeavored, while in Paris, (on the occasion of the visit of the British Association of Gas Managers) to procure such information as was obtainable on the subject of lighting by electricity, as partially adopted in that city-its cost, practicability and effect, for the purpose of ordinary illumination. I was further requested to prolong my stay, in order to witness the effect of the extensive preparations then in progress for a general illumination, by means both of gas and electricity, on the 30th of June, the day appointed to be observed as a National Fete. By the courtesy of M. Denayrouse, the Managing Director of the Electric Light Company, the members of the Association were permitted to visit the works of the company in the Avenue de Villas, and there inspect the apparatus in preparation for producing the electric light; and afterwards, on the same evening, were admitted to the Concert at the Orangerie, at which place 52 electric candles are in use, and where the engines and machines were open to the inspection of the members. Subsequent interviews were arranged between M. Jablochkoff (the inventor of the electric candle) and five of our number, including the President of the Association and two American engineers, one being the Editor of the American Gas Light Journal. At each of these interviews I was present, and am pleased to testify to the patience and attention with which our inquiries were met. 66 The system adopted by the company, and to which my attention was mainly directed, as being the one almost exclusively employed in Paris, is that devised by M. Jablochkoff, the distinctive features of which are, as is well known, the production from the same source of more than one light, and the employment of what is termed the candle." This latter is an ingenious substitute for the lamp and regulator, with their attendant conveniences, and consists of two carbon rods, placed vertically side by side, and having between them throughout their entire length, and isolating substance called kaolin. The intervening space between the rods being just sufficient to admit of the formation of the voltaic arc, is temporarily bridged over at the tip, which latter is ignited by the electric current, and the candle burns slowly down, the kaolin being consumed at the same rate as the carbon. I am able to produce one of these candles for the inspection of the committee. They were stated to cost 75 centimes each. Each lantern is provided with four, and sometimes five candles, placed in sockets upon a brass table; and the electric current is communicated to one or other of them, as may be desired by means of a commutator, worked with a switch arrangement, attached to every lantern. As each candle lasts, while burning, only from one and one-quarter to one and one-half hours, constant attendance is necessary for the purpose of changing them-a difficulty, which it seems possible might be overcome by means of some automatic arrangement. The candles are enclosed in thick opal globes, 50 centimetres in diameter, equal to 19.68 inches, English measure, which, while they diffuse and soften the light, effectually subduing its piercing brilliancy, very considerably diminish its intensity. It is admitted that the loss in this way amounts to 30 per cent. of the light generated; and, judging from the effect of similar globes upon gas-light, I believe it to be very much more. Each candle is estimated by the inventor to give the light of 110 carcel lamps, which, at 9.6 candles per lamp, equals 1,056 sperm candles; from this has to be deducted the 30 per cent. absorbed by the globe, leaving 739.2 sperm candles, as the available light given by each electric candle. This, however, is an evident exaggeration. I estimated the light at about 200 candles, and others with whom I conversed considered it comparable with about 15 ordinary gas burners-a value pretty much the same as my own. The machine employed for producing the electricity is the magento-electric machine of M. Gramme-a compact and powerful apparatus, to which, I believe, I am correct in attributing any practical success which has yet been achieved in the direction of distributing the light from more than one focus. As full descriptions of this machine have appeared in several scientific periodicals* in this country, it is probably unnecessary that I should refer to it in detail. Two sizes are now made— one capable of sustaining four lights placed upon one circuit, and a larger one for sixteen lights upon four circuits. The cost of the smallest is 3,000 francs, or £120 each, exclusive of a four-horse engine and boiler, the power required to drive them being about one-horse power per candle. The maximum distance from the machine at which the current can be advantageously transmitted is 800 yards; and it also transpired that all the candles upon the same circuit or machine are of uniform intensity, it having been found extremely difficult, if not impossible, to produce them of varying intensity from the same source. Amongst others, the following places are lighted by the method above described : Place de l'Opera. Avenue de l'Opera. Place du Théatre Francais. Front of the Corps Législatif. * See "Engineer," Dec. 21st, 1877. See "Engineering," July 26th, 1878. This is an under-estimate; for in every case, so far as we had opportunities for observing, a much greater power was employed. It would be safer to take it at two h. p. per candle. Orangerie (at corner of the Gardens of the Tuileries). Workshops of the Electric Light Company. Its effectiveness, as thus displayed in some of the most frequented parts of the city, with the brilliant appearance of which it is impossible not to be impressed, is beyond question; and goes far to prove its general adaptability for open air illumination, and for the lighting of large public buildings or workshops. The eye does not appear to experience any but the slightest sense of fatigue, the otherwise intolerable intensity of the light being almost entirely subdued, but there still remains an objection, which it is thought, by some, to have considerable force, namely, that it imparts to the countenance a somewhat unnatural hue. Its employment, however, at such places as the Magazin du Louvre, the Orangerie and the Hippodrome, seems to show that whatever importance may attach to this objection, is outweighed by other considerations. At the Hippodrome, an immense oval building, 341 ft. long, by 223 ft. wide, which is crowded nightly, an excellent effect is produced by 14 reflected electric lights, and 20 suspended "candles," the balconies and orchestra being in addition, lighted with gas. When, during one portion of the performance, it was desired to darken the arena, this was readily effected by withdrawing the 14 reflected lights; and these, after a short interval, were again put forward without any apparent difficulty. At the nightly concerts at the Orangerie, the orchestra and stage are lighted entirely by electricity, as are, also, the long promenade and hall. The promenade is about 32 yards wide, and the candles are placed about 26 yards apart, so as to form one row down the centre. I was able to read a newspaper without the slightest difficulty, at the furthest distance from any of the candles. It was here, however, that in the course of the evening I observed a considerable unsteadiness in the light, as though the engine power was not being properly maintained; and a disagreeable pink light |