300 Hare’s Blowpipe. 
mences. ‘he elevation of the sides of the gasometers 
above the horizontal partition or diaphragm, constitutes an 
‘external cavity, in which water may be poured so as to load 
them sufficiently. A, B.C. D. cistern, E. ¥. partition di- 
viding it, H. gasometer, or self-regulating reservoir of hy- 
drogen, G. gasometer for oxygen, I. 1. two pipes closed at 
top and inserted air tight into the gasometer, L.M. two 
smaller pipes in the axis of those last mentioned, open at 
top, passing water tight through the bottom of the cistern 
and communicating with the blowpipe n. 0. m. m. exten- 
sion of the pipe M. by means of which, oxygen may be in- 
troduced from the iron bottle f* P.P. rods which pass 
through holes in a sort of gallows, so as to regulate the 
movements of the gasometers, and stop them by the bands 
and screws R. RR. at any height desired; Q. Q. cocks, for 
draining the pipes L. and M. of any moisture which may 
condense in them. f 
This method of affording a regulated production and 
store of hydrogen gas, is somewhat analogous to that of Gay 
Lussac ; but has this superiority; that the pressure is more 
equable, need not be greater than useful, and may be 
lessened at pleasure, so as not to have the tendency to leak- 
age through the cocks, or any pores in the apparatus use- 
lessly increased. Hydrogen is peculiarly subtile, and will 
escape when other gases will not. 
Fig. 6, and Fig. 7,F represent self-regulating reservoirs 
of hydrogen, more closely upon the principle of Gay Lus- 
sac. I had availed myself of this principle to regulate the 
production of fixed air from carbonat of lime before I heard 
of its adoption by that eminent chemist. A (Fig. 8? Ed.) 
a partition dividing the cask into two apartments, the lower 
the largest. B B a false bottom, full of holes, raised above 
an inch from the real bottom of the cask. C a copper or 
leaden pipe, inserted at its upper end into the partition, and 
extending downwards a little beyond the false bottom. B 
* The iron bottles used in commerce to confine quickstlver answer admi- 
rably well. The narrow end of a gun barrel usually fits them, and if not 
large enough, a section may be made near the breech where the barrel 
thickens. 
It may be luted into the bottle with elay or lime and white of egg, and a 
longer pipe is then easily luted to the breech, where it cannot be injnred 
by the fire. 
1 Wig. 7 and 8 ?>~Zdilor. 
