IX. MISCELLANEOUS. 



251 



floating in powder magazines and stores in the form of fine dust. After a series 

 of experiments it was ascertained in the most conclusive manner that all safety 

 lamps wholly or partially constructed of gauze are useless for this purpose, the 

 gauze failing to exclude the powder dust, which, collecting inside the lamp ex- 

 plodes. Now the flame of a powder explosion is so much more violent than that 

 of gas that it instantly penetrates the gauze and carries through with it 

 incandescent particles of powder. 



This patent safety magazine lamp has, therefore, been constructed on the 

 following principle : 



To prevent risk of explosion 

 from the entry into the lamp 

 of the fine powder dust which 

 may be present in a powder 

 magazine or store, the air pas- 

 sages which supply this lamp, 

 and also the exit passages for the 

 burnt air from the flame, are con- 

 structed so that the air must 

 pass under and over a series of 

 screens. Air to support com- 

 bustion enters the lamp under 

 an inverted outer ledge, and 

 then passes through holes made 

 in the casing to a narrow space 

 formed by an inner lining ; so 

 that the air must first pass up 

 to reach the holes in the casing, 

 then down the inner space, and 

 finally up another narrow space 

 before entering the lantern. 

 The top part of the lamp is 

 constructed on substantially the 

 same principle, that is, the exit 



air passages are made zig-zag ; but, in case they ever become clogged with 

 soot, two out of three parts which form the passages are hinged to the 

 casing, and are secured in place by a spring lock. When these parts arc 

 unbolted they can be turned back on their hinges and easily cleared of any 

 soot that may have become deposited therein. 



The bottom and sides of the lamp are the only parts fixed to one another, 

 and the burner is dropped in through the top of the lamp, which is then 

 secured with a spring lock as already mentioned. 



Every detail of the outer casing of the lamp has been carefully con- 

 sidered, and there are no projecting parts where dust can accumulate and 

 settle. The lamp has a bull's-eye lens in front; the side lights are glazed 

 with glass one-eighth of an inch thick, protected by strong copper wire. The 

 handle moves on a pivot. The burner is a f -inch flat wick, and a reflector is 

 added to increase the brilliancy. The lamp and lantern are made of copper, 

 bright tin, or tin japanned. 



The highest temperature of the outer casing of the lantern has been 126 

 the exploding temperature of powder being 600. 



Spectacles, for shooting. 





G. W.Richter. 



