72 



BENJ. PIKE 8, JR., DESCRIPTIVE CATALOGUE. 



Fig. 514. 



Fig. 515. Retort stands with 



rectangular iron base, 

 ten inches long, hav- 

 ing two rods and six 

 rings of the size of 

 the former. 



Price, $3,00. 



Cooper s Lamp Furnace. (Fig. 516, as above.) A lamp 

 which is made of an elongated form, and is furnished with 

 two rows of broad wicks, the whole or part of which may 

 be lighted at once. Professor Faraday recommends this 

 simple furnace as valuable for the heating of tubes, or any 

 long and narrow vessel. Near the ends are two twisted 

 wires, for the support of the tube to be heated. 



Price, $2.00. 



Knight's Assay Lamp. (Fig. 517, next page.) Such is 

 the name given by Mr. Knight, Foster Lane, to an extremely 

 useful Argand lamp, adapted to heat retorts, and for general 

 chemical purposes. A is a flat, short, cylindrical vessel, for 

 containing the oil. B is a double cylinder of tin, about an 

 inch in diameter. The outer cylinder passes through, and 

 is soldered air-tight to the oil vessel ; the inner cylinder 

 passes from the holes below to the centre of the flame. 

 The oil and the cotton pass between the two cylinders. B 

 is furnished with a screw below, which screws on to the foot 

 c. D is a rack and pinion to regulate the height of the wick. 

 E, E, E, are three wires, formed into a frame-work to support 

 anything which is to be heated ; these wires slide up and 

 down in sockets on the sides of A and c. F is a hole for 

 the supply of oil. There is usually a copper tube placed 



