A2 Hydro-orygen Blowpipe. 
the gas, the efflux being regulated by B, or preferable by a cock 
of the ordinary construction, one of which kind should be inter- 
posed at a convenient position between the valve-cock, B, an 
cylinder, A. 
T, represents a glass tube, which, by due communication with 
the interior, shews the height of the water, and consequently the 
quantity of gas in the vessel. 
, H, represents a gauging apparatus, consisting of a cast iron 
flask, of about a half a pint in content, and a glass tube of about 
a quarter of an inch in bore, which should be at least five feet in 
height. The tube is secured air-tight into the neck of the flask, 
so as to reach nearly to the bottom within. The flask is nearly 
full of mercury. Under these circumstances, when a. communica- 
tion is made, by a leaden pipe between the cavity of the flask and 
that of the reservoir, an equilibrium of presure resulting, the extent 
of the pressure is indicated by the rise of the mercury in the tube. 
In order to generate hydrogen for the supply of a reservoir like 
that represented by the preceding figure, I have employed the 
vessel represented by fig. 7. This vessel, by means of a suitable 
aperture, susceptible of being closed by a screw plug, is half fill- 
ed with diluted sulphuric acid. Being furnished with a tray of 
sheet coper, D, punctured like a coal sieve, and supported by a 
copper sliding rod, E, strips of zine are introduced in quantity 
equal to the capacity of the tray. ‘I'he sliding rod passes through 
a stufling-box, F’, at top of the reservoir, so that the operator may, 
by lowering or raising the tray, regulate or suspend the reaction 
between the zinc and its solvent, accordingly as the supply 
hydrogen is to be produced, suspended, increased, or diminished. 
e communication with the reservoir is open and regulated 
by means of a cock, P, furnished with a gallows screw, G, for 
the attachment of a leaden pipe, as above described, in the pre 
cess for supplying the reservoir with oxygen. ; 
Another apparatus for producing a supply of hydrogen, 18 Te? 
resented in fig. 6. It consists of two similar vessels of boiler 
iron, each capable of holding forty gallons. ‘They are lined in- 
ternally with copper, being situated upon a wooden frame, S° that 
of one and a half inches. of 
The upper vessel is surmounted by a globular copper vessel, 
about twelve inches in diameter, which, from its construction, 
renders it possible to introduce an additional supply of concen: 
trated acid, while the apparatus is in operation, without 
the pressure within the reservoir, by permitting the excess above 
the pressure of the atmosphere to escape. ‘This object 8 accom 
plished as follows :— 
