192 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



instrument in its general arrangement is the same as the 

 usual table air pump, but made in a more elegant style, 

 being framed wholly of brass and highly finished. Between 

 the pump barrels and the receiver plate, there is a large 

 stop-cock, which, when closed, prevents any leakage from 

 the various joints into the receiver. The mercurial gauge 

 has a metallic scale, and is placed within a glass shade, and 

 supported on a large stop-cock, by which communication or 

 not may be made with the receiver. 



Price, largest size, $75.00. 

 " smaller " $50.00. 



Large Double Barrel Air Pump. (Fig. IT 9, as below), 



