SAFETY-LAMPS. 207 



no, gentlemen lamp-makers, it shall not be permitted for you 

 to have all the credit that wire gauze can bring, leaving Davy 

 all the obloquy. Take the Davy lamp, and improve it if you 

 can ; but so long as you use wire gauze, call it a Davy lamp, 

 and yourselves its improvers. 



It would be tiresome work to specify a tithe of the lamps 

 which have sprung up from the first simple idea. The very 

 safest of them, Roberts' s, may be described as a Davy lamp 

 surrounded by a glass, and supplied with air through layers of 

 wire gauze below; a corresponding series of wire-gauze layers 

 above giving issue to the products of combustion. This lamp 

 I have never known to explode under the severest trials ; but 

 it has a fatal defect it is too fastidious. Immediately the air 

 which surrounds it becomes a little impure, it gives a puff, 

 goes out, and leaves the miner in darkness, to find his way out 

 of the mine the best way he can, or to relight the lamp-wick by 

 a lucifer ! There is the present lamp of Dr. Clanny, glass 

 below and wire gauze above. There are the Miisler and the 

 Eloin lamps, both well spoken of in Belgium ; which, like the 

 present lamp of Dr. Clanny, make a point of feeding the wick 

 with air per descensum, so that, air being heavier than explo- 

 sive gas, the latter is to some extent filtered away. 



I shall make short work of this numerous fry of modified 

 Davys. Some are worse than the prototype, under all cir- 

 cumstances; and some better, until the glass sheath" with 

 which most or all of them are supplied gets broken a con- 

 tingency of such frequent occurrence that, although the idea 

 of glass appears to have suggested itself to Davy, he soon dis- 

 carded it. Nevertheless the Miisler and Eloin lamps, both 

 much used by the Belgians, have glass in their construction ; 

 and though the glass cracks occasionally, yet, like many 

 varieties of our English glass safety-lamps, they are said not 

 to be practically damaged by the accident. 



Space admonishes me to make deductions, if such I have 

 to make, and conclude this sketch of safety-lamps. If I have 



