WIRE-GAUZE SAFETY-LAMP. 



in the Horrington mine, near Sunderland ; that if the infnla- 



tion of the lamp were made with hot water, the fire-damp 



burned filentl)' at tlie wick, and did not explode within the 



lamp, as formerly. T- is he afcertained to be owing to the 



fteani ; and he farther dilcovered, that one part in volume 



of fteam to two of the moft explofive mixtures deftroyed 



their inflammability. A fimilar effeft of lleam had been 



before noticed by Von Grotthus, in the Szd volume of 



, the Annales de Chimie, but had not been applied to any 



; ufeful purpofe. In December of the fame year. Dr. Clanny 



conllrufted a fteam fafety-lamp, which he exhibited to the 



1 Society, for preventing accidents in coal-mines, and received 



i their unanimous thanks; and in 1817 he received a gold 



medal from the Society of Arts for the difcovery. 



In the fteam fafety-lamp there is a refervoir of water at 

 the top of the lamp, which is a clofed tin box, or ciftern. 

 The water is kept boiling by the flame of the lamp, and 

 the fteam mixing with the carburetted hydrogen prevents 

 all riflv from explofion. The air is fupplied through a 

 tube to the upper part of the ciftern above the water, and 

 defcends, mixed with the fteam, down two other tubes, into 

 the body of the lamp. By this means, the fire-damp burns 

 filently and fteadily at the wick of the lamp alone for any 

 length of time. Should the carburetted hydrogen exceed 

 the proportion of atmofpheric air for fupporting combuf- 

 tion, the light is extinguiflied, but this can rarely hap- 

 pen. It has alfo the valuable property of keeping cool 

 throughout every part, and under all circumftaiiees ; this 

 is eff^efted by the evolution and motion of the fteam. 

 This lamp, fays Dr. Clanny, is now well known to 

 burn moft brilliantly in an atmofphere of fire-damp, even 

 after the original fafety-lamp has had the fire-damp ex- 

 ploded within it. The fteam-lamp has now been extenfively 

 ufed in feveral of the northern collieries. Its great recom- 

 mendation over other inventions is the fuperior light which 

 it affords. Thefe lamps are made of the ftrongeft tinned 

 iron, with a flat glafs in front, three-eighths of an inch in 

 thicknefs. They are exceedingly ftrong and durable, and 

 coft about twelve ftiillings, but might be manufaftured on a 

 large fcale for half the price. 



Fig. 4. reprefents the ftiort tube by which the air enters 

 into the tube b, and this tube fupports the water-ciftern c at 

 the top, being fitted into the tube a at the bottom, fo as to 

 be taken out and replaced when the water is to be poured in 

 or removed from the ciftern c. The air which afcends the 

 tube b mixes with the fteam of the water-ciftern, and pafles 

 down the two tubes d, d, to fupport the combuftion of the 

 flame, and afterwards afcends by the fide of the ciftern 

 through the chimney of the lamp. Thefe tubes are clofed at 

 the bottom, and perforated oa the fides, to retard the pro- 

 grefs of the air, and mix it with the fteam before it reaches 

 the fl^amef. The bottom is air-tight ; ythe glafs, and g the 

 oil-lamp. Thefe lamps are twelve inches in length, exclu- 

 sively of the chimney. They ftinild be cleared of water, 

 and well dried, after they have been in ufe, that tftey may be 

 more durable. When the lamp is firft lighted it is neceflary 

 to eftablifti a current, which is beft done by turning the 

 lamp, fo that the tube a may be expofed to the current of 

 air ; this will be effeAed in five minutes, and the lamp will 

 afterwards continue to burn regularly and fteadily. 



Dr. Clanny farther applied the fame principle to the con- 

 ftruftion of a larger lamp, in which were three wicks to 

 burn the inflammable air as it was made to iftue through the 

 oil ; this is intended to confume the hydro-carburetted gas 

 as it ruflies from a blower. 



In the hiftory of ufeful inventions, perhaps no inftance of 

 fupinenefs can be adduced, among thofe iutereftcd in any dif- 



covery, which equals the inattention fliewn for feveral years 

 by the coal-workers in the north to the valuable labours of 

 Dr. Clanny. We had an opportunity of examining his 

 lamp in 18 13, and were fatisfied with the complete fecurity 

 which it affords. At that time, however, fo far from re- 

 ceiving the patronage he highly merited, he was regarded 

 by many with a ilrange jealoufy, as an officious intruder into 

 the myfteries of mining ; myfteries which he had no right to 

 inveftigate. To Dr. Clanny, however, the firll difcovery 

 of a fafety-lamp is undoubtedly due ; and we have no hefita- 

 tion in aflerting our belief that his original fafety-lamp is the 

 moft fecure of any that have fince been invented, where 

 dangerous parts of the mine are to be explored, on account 

 of its more complete infulation, and its greater ftrength. 

 His lamp had alfo the merit of firft fuggefting the poffibility 

 of infulating the flame in the different lamps which have fince 

 been conftrufted. 



The attention of the public was at length direfted to the 

 dangerous fituation of the men working in the mines by a 

 few gentlemen, who formed a fociety, in 18 13, at Sunder- 

 land, entitled A Society to prevent Accidents in Coal-Mines. 

 Dr. Gray, reftor of Bifhop-Wearmouth, an aftive mem- 

 ber of this fociety, invited fir H. Davy, in 1815, who was 

 then on a vifit in the north of England, to examine the col- 

 lieries with a view to affift the efforts of the fociety to pre- 

 vent the accidents to which they were fubjeft. From the 

 information communicated to him by perfons employed in 

 the mines, lie was induced to commence a feries of experi- 

 ments on carburetted hydrogen gas, which led to feveral \in- 

 expedled refults, not lefs interefting to fcience than ufeful in 

 their application to the arts. Before proceeding to defcribe 

 thefe, we muft notice the labours of Mr. Stephenfon, an en- 

 gineer in the Killingworth main colliery, who previoufly to 

 this time had, as he afferts in a pamphlet on the fubjeft, enti- 

 tled " ADefcriptionof the Safety-Lamp invented by George 

 Stephenfon," made the difcovery that inflammable air will 

 not explode through fmall apertures. In the fame pamphlet 

 he ftates,that a lamp conftrufted by him on this principle was 

 tried in the above colliery on the 2 1 ft of Odober 18 15, 

 the lamp being carried in fafety into a part of the mine 

 where a ftrong blower of inflammable air was iffuing. The 

 experiment, he adds, was immediately repeated in the pre- 

 fence of two perfons employed in the works. 



Thefe lamps, judging from Mr. Stephenfon's own de- 

 fcription, yielded but a feeble light. They were after- 

 wards improved ; but thefe improvements bear fo clofe a re- 

 femblance to parts of fir H. Davy's lamp, hereafter to be 

 defcribed, that we conceive Mr. Stephenfon muft labour 

 under no fmall difficulty in eftablifliing his claim for their 

 original invention. The queftion, at prefent agitated with 

 much warmth, can only be decided by a reference to well- 

 eftablifhed dates and authentic evidence ; an inveftigation not 

 fuited to the nature of the prefent work. 



We have little doubt that the infulation obtained in Dr. 

 Clanny's lamp by water firft fuggefted to Mr. Stephenfon the 

 poffibility that fmall apertures might intercept the extenfion 

 of the flame as effeftually as water. On this fuggellion his 

 firft lamp appears conftrudled, the tube which admitted the 

 air being covered with a Aide, to diminifli the aperture at 

 pleafure ; but the quantity of air which could be fafely ad- 

 mitted through one aperture being inadequate to the fupport 

 of the flame, it was obvious that the only way to enfure 

 both light and fafety was to increafe the number of apertures, 

 diminifliing the fize of each. In this manner, it appears that 

 Mr. Stephenfon proceeded mechaEiically, without a corredl 

 knowledge of the properties of the gas, or the principles 

 on which the eftcdls were produced. Wc think, however, 



that 



