THE EAHTH. 



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contrivance to supply sufficient light for tlieir operations. This 

 is by a great wheel, the circumference of which is beset with 

 fiints, which striking against steels placed for that purpose at 

 the extremity, a stream of fire is produced, which affords liglt 

 enough, and yet which does not set fire to the mineral vapour. 



riial- mines, in order to find, if possible, a remedy for preventing such 

 c«ta>trophes. 



Dr William Reid Cianny, of Sunderland, had, in the year 1813, turneii 

 hia attention to the construction of a lamp which wou'd burn amongst in- 

 flammable air, and, thou!»h an explosion might take place in the lamp, 

 would not communicate flame to the external sunounding air. This he 

 accomplished by means of an air-tight lamp with a glass front, the flame 

 of whirh was supported by blowing air from a pair of small bellows through 

 a stratum of water in the bottom of the lamp, while the heated air passed 

 through water by a recurved tube at the top. By this process, the 

 air within the lamp was completely insulated from the external air, 

 and 't appears that this was the first lamp that ever was taken into a 

 body of inflammable air in a coal-mine at the exploding point, without pro. 

 ducing an explosion of the surrounding gas. Dr Cianny made another lamp 

 upon an improved plan, by introducing into it the steam of water produced 

 from a small vessel at the top of the lamp, heated by the flame. For these 

 inventions the Doctor twice received the thanks of " The Society for prevent- 

 ing accidents in CoaUMines;" and he also received the silver and afterwards the 

 gold medal from the Society of Arts in London. Although these lamps, in. 

 vented by Dr Cianny, were upon philosophical principles, displayed much 

 Ingenuity, and were absolutely safety-lamps for mines, yet their construe, 

 ticn prevented them from being generally used. It appears that nothing 

 farther was attempted in this important matter, until the accident at Felling 

 colliery, as before noticed, when Sir Humphrey Davy, Mr James Stevenson, 

 engineer, Killingworth colliery, Newcastle, and Dr John Murray of Edin. 

 burgh, brought forward safety-lamps, in the year 1816, each constructed up- 

 on difterent principles. Sir Humphrey Davy's lamp was made of fine iron 

 wire gauze, without any glass ; that of Mr Stevenson was made of a stronar 

 glass cylinder having a metal plate at top, and another at bottom, perforated 

 with very small holes to permit the air to pass to and from the lamp ; and 

 that of Dr Murray was a glass lamp, or rather lanthorn, to which good at. 

 mospheric air was brought by means of a long leather pipe from the air. 

 course. Of these Dr Murray's lamp was not applicable but in a very few 

 lases ; the lamps of Sir Humphrey Davy and Mr Stevenson were both com- 

 plete safety-lamps in their primiple, and are applied in practice ; but that of 

 Sir Humphrey Davy is decidedly the best, and is generally used in Great 

 Britain. Having no glass it is not easily injured, and suflicient light for the 

 miner passes through the wire gauze. To each of these gentlemen the woild 

 is highly indebted, and in particular the mining interest of Great Britain for 

 their individual exertions. The safety-lamp of Sir Humphrey Davy was 

 instantly tried, and approved of by Mr Buddie, and the principal mining en. 

 gineers at Newcastle. No one was more zealous to prove its safety and in. 

 troduce it into the mines, than the Rev. John Hodgson, of Heworth. Kb 

 descended the minas, entered amongst the inflammable air, aiid fully satisfied 



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