2G4 



♦ KNOWLEDGE • 



[iMAY 4, 1883. 



THE CRYSTAL PALACE ELECTRIC 

 AND GAS EXHIBITION. 



FINAL XOTICE. 



rpUAT Messrs. J. Defries it Sons are no novices in the 

 X. art of decorative fitting is amply demonstrated by 

 the charming display made by them in conjunction with 

 the Ciulcher Electric Light Company. Anything more 

 chaste in design, more delightfully soft and elegant in con- 

 ception, is beyond our highest imaginative flights. Any 

 eflbrt aiming at more than the briefest description would 

 necessarily be futile. Suffice it to say, therefore, that if 

 anything were wanting to try, to the utmost, the capacity 

 of the electric light for decorative and illuminating pur- 

 poses, that want is ready to be supplied ; and when we 

 remember the advantages, from a sanitary point of view, 

 pertaining to the adoption of the new illuminant, the pre- 

 diction that it will, before long, make its way, at least, into 

 the mansions of the wealthy, strikes us as a very safe one. 

 We say the wealthy advisedly, for it is practically beyond 

 dispute that the incandescent syst3m is somewhat more 

 expensive than gaslight, while the arc system is not ap- 

 plicable to domestic lighting. The ditrerence in cost is, 

 however, not so great as to prevent many consumers, even 

 in business houses, adopting the electric light on account 

 of its many advantages. The Giilcher-Crookes system is 

 one of the most perfect at present in the market. It 

 embraces a useful and economical dynamo, an arc 

 lamp which equals the Fyfe-Main in steadiness, and 

 a good incandescent lamp. The peculiar features about 

 the system are that both forms of lamp are maintained in 

 the same circuit, the arc lamps being fed in parallel circuit. 

 We have for a long time wondered why efforts in this 

 latter direction have not been more extensively made, and 

 it is still somewhat surprising that this is the only system 

 which attempts it. The electro-motive force or pressure of 

 the current generated by the Giilcher Dynamo is only 60 

 volts (a volt being, roughly speaking, the electro-motive 

 force of a single Daniell cell), no matter how many lamps 

 are in circuit, while such a machine as the Brush, main- 

 taining 40 arc lamps in a single circuit, has to provide a 

 current of something like 2,000 volts, a current which, to 

 say the least, is highly dangerous to those who have any- 

 thing to do with it. So impressed are we with the advan- 

 tages inherent in the Giilcher Company's system, that we 

 shall doubtless find occasion to say more concerning it in 

 an early number. 



Tiie Lever Arc lamp has been removed, and its place 

 taken by the Werdemann Company, who have erected 

 three of their Lea Arc lamps in the tropical section, five 

 others being suspended over the centre transept. The latter 

 are, however, naked lights, and are an intolerable nuisance 

 to anyone sitting in the chairs opposite the orchestra, the 

 irregular glare dazzling one's eyes terribly. Surely but 

 little is expected to be gained by compelling people to see 

 a light in this manner. 



The Gas Section has not brought forth any novelties 

 since our last notice, and the Bower-Griscom lamp re- 

 mains the champion. The principle of the " Regenerative " 

 lamps i^ deserving of some attention, the first form on 

 this principle that was introduced being that of Messrs. 

 Siemens. It is tolerably well known that the illumination 

 produced by the burning of gas is due to the presence of 

 minute particles of carbon. By raising the temperature of 

 the flame, combustion is rendered more perfect, and the 

 illumination, perforce, more brilliant. In the Regenerative 

 Burner, this effect is produced by supplying heated instead 

 of cold air to the flame. This is accomplished by utilising 



the heated products of combustion, as they pass away from 

 the flame, to heat the gas as well as the air as it passes 

 towards the flame. The burner is illustrated by the ac- 

 companying diagram. The gas in a cold state passes 

 through the gas-chamber, A, and gas-tubes, B, to the point 



of ignition, C. Cold air enters the air-chamber, D, and in 

 passing to C, between the tubes B, it is heated, and then 

 distributed to the flame by means of a circular collar. The 

 flame burns around the porcelain cylinder, H, and turning 

 over the top of it, descends into the interior of the burner 

 or regenerative heating chamber, E — an effect resulting 

 from a continuous current in the chimney, G. The tem- 

 perature of the heating chamber is said to be 900° C, the 

 consequence being that the gas and air in the surrounding 

 chamber (during the process of their ascent from the 

 Ijottom to the top of the burner) are raised to a similar 

 temperature, thus increasing the illuminating power. Out- 

 side the burner is a jacket of thin metal, I, between which 

 and the burner a current of cooler air ascends to prevent 

 the overheating of the burner, and to add to the supply 

 of air to the flame. K is simply a glass cylinder for pro- 

 tecting the flame. Looked at from below, the burner looks 

 uncommonly massive, and not over pretty, but its efficiency 

 is admitted to be very high. To the Londoner, it is not 

 altogether a novelty, as it has been in use in certain parts 

 of the City for some months. Some interesting figures 

 are given by Colonel Haywood in his report to the Com- 

 missioners of Sewers on the Holliorn experiment. The 

 illuminating power of each lamp is .stated by the company 

 to be equal to l;?0 candles, but no photometric observations 

 have been made by the Commission. The ordinary bats- 

 wing burner produces a light of about 14 candle-power, so 

 that the illuminating power claimed for the new lamps is 



