THE SAFETY-LAMP. 265 



mines, or at least to diminish their frequency, and 

 prizes were offered for the discovery of new methods 

 of lighting and ventilating mines. Dr. William Reid 

 Clanny, of Bishopwearmouth, presented to this society 

 a lamp which burned without explosion in an atmo- 

 sphere heavily loaded with fire-damp ; for which in- 

 vention the Society of Arts awarded him a gold 

 medal. The Rev. Dr. Gray called the attention of 

 Sir Humphry Davy to the subject, and that eminent 

 chemist visited the coal mines in 1815 with the object 

 of determining what form of lamp would be best 

 suited to meet the requirements of the coal miners. 

 He invented two forms of lamp before discovering the 

 principle on which the present safety-lamps are con- 

 structed. This principle the property, namely, that 

 flame will not pass through small apertures, had 

 been, we believe, discovered by Stephenson, the cele- 

 brated engineer, some time before; and a somewhat 

 angry controversy took place respecting Davy's claim 

 to the honour of having invented the safety-lamp. 

 It seems admitted, however, by universal consent, that 

 Davy's discovery of the property above referred to 

 was made independently, and also that he was the 

 first to suggest the idea of using wire-gauze in place 

 of perforated tin. 



In comparing the present frequency of colliery 

 explosions with what took place before the invention 

 of the safety-lamp, we must take into consideration 

 the enormous increase in the coal trade since the 

 introduction of steam machinery. The number of 



