90 



BENJ. PIKE S, JR., DESCRIPTIVE CATALOGUE. 



in other experiments a coiled wire, a piece of charcoal, &c. 

 The whole is intended to show that oxygen and other gases 

 ire supporters of combustion. Sometimes the mouth of the 

 leflagrating jar is ground flat, that it may be covered with 

 t piece of plate glass. Price, 75 cts. to $1.50. 



Fig. 544. 



Fig. 543. Deflagrating Ladle. (Fig. 544.) 

 This cut represents a deflagrating ladle 

 for burning small portions of phos- 

 phorus, sulphur, &c., in oxygen gns. 

 It is attached to a cork, fitting the neck 

 of a bell glass. Price, 2 Sets. 



Davy's Safety Lamp. (Fig. 545.) 

 An instrument to prevent the fatal ex- 

 plosion of fire damp, to which miners 

 are exposed when working in coal 

 mines ; it is constructed on the princi- 

 ple that flame will not penetrate a fine 

 wire gauze, and consists of a lamp of 

 brass or tin, having a stout wire frame, 

 at the top of which is a plate and ring 

 by which the lamp is held ; within the 

 wire frame is a cylinder of wire gauze 

 inclosing the flame, but permitting a 

 sufficiency of light to pass through ; at 

 the side is a feeder for oil, and there is 

 passing througli the bottom a wire to pick the wick. 



Price, of best brass mounted, 85.00. 

 " of plainer, - $3.00. 



" of tin, - - $2.00. 



Fig. 546. 



Flameless Lamp. (Fig. 

 546.) The aphlogistic, or 

 flameless lamp, having a glass 

 instead of metal tube for sup- 

 porting the wick ; a fine pla- 

 tina wire about fifteen inches 

 long, and wound in the form 

 of a spiral spring, is placed 

 partly over the end of the 

 wick. The lamp thus pre- 



