for technicai analysis of Petroleum. 235 
and carefully ground into its seat. The length of the spindle 
should be one-fourth of an inch less than the distance from the 
seat of the valve to the bottom of the orifice upon the inside of 
Small quantities of every variety of bituminous and img 
phe 
Y comparison. The cost of the ‘ 
Tetort with goose-neck and valve, 
made by the most skillful work- 
Pipe; bb are the discs; cece are 
the bands left when the caps are 
turned off; dd is the frame and e 
*t-screw 
Which q represents the upper cap, 
4 the lower cap, ec the gas-pipe, d 
He escape pipe, e the spindle, ff ||< 
°penings in he same for e tl 
ang Poss 9999 the diaphr 
and hhh i the spiral spring. 
, R. L, April 30th, 1866. 
