March 30, 1883.] 



♦ KNOWLEDGE ♦ 



197 



and apparatus requisite for the purpose. It is stated, 

 however, that arrangements are nearly completed for 

 supplying this air locally, by means of a small apparatus, 

 about the size of an ordinary gas-meter, which ■will have a 

 capacity sufficient to supply a dozen burners. At present, 

 the cost for air is about fourpence for every thousand feet 

 of gas consumed. Considering that there is a clear saving 

 of 50 per cent, in the gas bill, this trivial cost for air is of 

 comparatively little moment. 



While we may conscientiously say the light is all that 

 could be desired so far as gas-light goes, there is to be con- 

 sidered the olijection there would be to the application of 

 the system to domestic purposes, consequent on the slight 

 hissing noise that attends this mode of illumination. 



In order to further reduce the cost of his system, Mr. 

 Lewis has, we liear, patented a burner in which the gas 

 is subjected to a pressure of 12 inches, and is then able to 

 induce the whole of the air necessary to complete the 

 combustion. 



M. Victor Poff, of Paris, exhibits a somewhat similar ar- 

 rangement. Two separate pipes run together until close to 

 the burner, one supplying ordinary gas, and the other air at a 

 very considerable pressure. The burner consists of a plati- 

 imm gauze cap, inside which is a cap of perforated steatite, 

 which covers the delivery-pipe. The mixture of gas and air 

 is, therefore, forced through the small holes in the steatite, 

 on the surface of which it bums, and in so doing renders 

 the adjacent platinum cap incandescent The luminous 

 efficiency claimed is the same as in the case of the system 

 previously described. The burner gives a soft, steady 

 light, and in Paris, where the inventor has the use of the 

 subways, it will most probably prove very successful, but 

 the difficulties it has to contend ^^^th in London are, we 

 fancy, too great to render its adoption generally prac- 

 ticable. This will be apparent when we reflect that it will 

 necessitate opening the streets to lay a fresh system of 

 pipes, to say nothing of the heavy expense that would be 

 incurred in maintaining the requisite air-pressure. 



M. Edouard Ser\-ier, another Parisian engineer, exhibits 

 in the Chinese Court the Clamond incandescent burner, in 

 ■which gas mixed with air at a slight pressure, but raised 

 to a very high temperature, burns in a cap or basket of 

 magnesia threads. These threads require, however, to be 

 renewed every forty hours, a fact that will weigh very 

 largely against them in the estimation of most consumers. 

 The light is good, but somewhat irregular, its brilliance 

 declining with the age of the magnesia. 



We regret our inability, through want of space, to refer 

 in detail to either of the regenerative burners. It is note- 

 worthy, however, that a new one has just been exhibited, 

 which is the production of Messrs. Bower ct Grimston. 

 The gas, accompanied by heated air, descends by vertical 

 tubes, ic, and, impinging on a refractory cone, is reflected 

 in a state of combustion in a horizontal plane. The flame 

 thus forms a horizontal ring, over it being a ring of fire- 

 clay, one of the functions of which is to reflect the light 

 emitted by the upper surface of the flame. The efficiency 

 of this Ijurner is seven candle-power per foot per hour, and 

 we believe that its excellence has e\oked the greatest in- 

 terest. We hope, therefore, to describe it more fully in 

 our next notice. 



Attention has been called to the rapid and considerable 

 deterioration of the plants in the Palace, and the cause is 

 attributed to the deleterious products arising from the 

 enormous amount of gas consumed every evening. There 

 are about sixty-two large lamps suspended from the roof, 

 and they consume together as much' as 9,500 feet of gas 

 per hour. A small proportion of imperfect combustion 

 would, therefore, suffice to charge the atmosphere very 



extensively with the highly injurious gas, carbonic oxide 

 (CO), perfect combustion yielding the much less hurtful 

 carbonic anhydride (COj). We believe, however, that gas 

 is in this case somewhat unfairly charged, and that age, 

 etc., has a great deal to tlo with the decay complained of. 



THE FACE OF THE SKY. 

 From M.\Rcn 30 to April 13. 



SPOTS, faculip, <tc., should be watched for as usn.il on clear days 

 The Zodiacal lig-ht is still visible after sunset. The aspect of 

 the Stellar Vault may be found from Map IV. of " The Stars in 

 their Seasons." Mercury, Venus, Mars, and Neptune are, for our 

 present purpose, invisible, while .Saturn must be looked at as soon 

 as ever it is dark enough for him to bo seen. Jnpiter, too, is now 

 rapidly approaching the west, and must be observed as early in the 

 night as possible. Ho travels away in a north-easterly direction 

 from 2; Tauri. To-night (the 30th)^at9h 32 m. 20 s., Satellite I. 

 will reappear from eclipse, as will II. on the 31st, at 8h. 35 m. 14 8. 

 p.m. ; Satellite III. will afterwards disappear in eclipse at 



9 h. 16 m. 11 s. to reappear 4 m. 49 s. after midnight. On April 4, 

 Satellite IV. will bo eclipsed at h. 33 m. 54 s., and reappear at 



10 h. 59 m. 48 s. A transit of Satellite I. vnll begin at 10 h. 43 m. 

 on the night of the 5th, and Satellite II. will follow it on to Jupiter's 

 face at 11 h. 32 m. On the 6tb, Satellite I. will be occulted at 

 8 o'clock, and reappear from eclipse at 11 h. 28 m. 3 s. On the 7th, 

 an occultation of the IlIrd Satellite will h.ippen at 8 h. 20 m. ; the 

 egress of the shadow of Satellite I. occurs at 8 h. 42 m. ; Satellite II. 

 reappears from eclipse at 11 h. 10 m. 3S s. ; and III. reappears from 

 occultation at 11 h. 11m. On the 12th, the student should look out 

 for a portion of the transit of Satellite IV. over Jupiter's face, for 

 the reason wc have more than once given. Ingress will take place 

 in twilight at 7h. 32 m., but egress may be observed at 8h. 32 m. 

 Uranus continues above 89 Leonis, but is now travelling somewhat 

 to the right. 



As the moon does not rise until after midnight to-night, and, of 

 course, gets later and later every night, we may regard her as 

 invisible up to April 10th, ■n-hcn she will be 2'9 days old at 

 Greenwich mean noon. At this instant she will be in Taums, 

 through which constellation she ■n'ill travel during the next twenty- 

 fom- hours, passing north of the Hyades. During the 11th she will 

 pass through the remaining jiart of Taurus, and be found at noon on 

 the 12th on the northern confines of Orion. Between h. on the 

 12th and the same time on the 13th she will pass into Gemini. She 

 will occult the Si mag. star \ Geminorum at 8 h. 20 m. p.m. on 

 AprU 13th at an angle of 58" from her vertex, the star reappearing 

 at an angle from her vertex of 342° at 9 h. G m. p.m. This is cal- 

 culated, of course, for Greenwich ; for other latitudes a correction 

 must obviously be made for the parallactic displacement of the 

 motm in the skv. 



IMPORTANT ELECTRICAL EXPERIMENTS. 



A SERIES of experiments were made with the Elphinstone 

 and Vincent Dynamo Machine, on the evening of Wednesday, 

 February 21st, at Messrs. Unwin Brotlicrs' in-intiiig-office, The 

 Gresham Press, Little Bridge-street, Ludgate-hill, in the presence 

 of a large and distinguished company, among whom were the 

 following : — Earl of Dunmore, Lord Saltoun, Count Gleichen, Vis- 

 countess de Vesci, Lady Elphinstone, Lady A. Mun-ay, Lady K. 

 Carnegie, Honourable C. Murray, Honourable E. Elphinstone, 

 Honourable A. Fraser, Sir E. Burnett, Bart., Sir Archibald Camp- 

 boll, Bart.; .\dmiral Herbert, Captains Tryon, R.N., Wilmot, E.N., 

 Brine, R.X., and Lieutenant Rogers, R.N., from the Admiralty; 

 Captain Shaw, Metropolitan Fire Brigade, and his two sons ; Mr. 

 and ilrs. Hichens, Mr. Fraser Rae, Mr. Spottiswoode, D.C.L., Mr. 

 Warren De La Rue, D.C.L., Mr. George Stephen (President of 

 Canada Pacific Railway), Mr. Wm. Winter, Mr. W. Elphinstone 

 &c., &c. 



The guests assembled in a large warehouse on the first floor, along 

 the ceiling of which, and grouped together, were suspended350Swan 

 incandescent lamps, each of 20-eandle power. These were brilliantly 

 illuminated, .and produced a most dazzling effect. Lord Elphin- 

 stone explained that the maehlno was capable of driving 416 Swan 

 lamps, but o^ving to delay only 350 could bo set up. Mr. Vincent, 

 in a brief address, explained the construction of the machine, re- 

 marking that it was the outcome of strictly following Faraday's 

 researches, excluding everything which tended to militate against 

 the conclusions drawn by that eminent philosopher. The dynamo, 

 which is claimed to be one of the most powerful continuous current 

 machines ever made, is of an entirely new design, patented by 



