Coal Gas. 473 
come into contact with the vessel H. There arc two sets of 
these stays, one shewn at M, and the other at N. 
There is also an iron pipe O, made fast in the centre of the 
gasometer by means of the stays, which slides over the upright 
pipe P, by which contrivance the gasometer is kept firm and 
steady, when out of the well ; it likewise prevents the gas from 
getting into the cast iron pipe P, and the copper pipe R, any 
where but through small holes made in the pipe O at S at the 
top of the gasometer, where the gas is perfectly transparent and 
fit for use. 
The pure gas enters the tube O at the small holes made in its 
top at S, and passes on through the tubes P and R to the lamps, 
where it is consumed and burnt. 
The seams of the gasometer are luted to make them air tight, 
and the whole well painted inside and out, to preserve it from rust. 
Fig. 2, shows a horizontal section of the lower hoop of the gas- 
ometer K at the part M, with its stays or arms, and the manner 
in which the iron pipe O, before described in fig. 1, sliding oa 
the tube P, passes through the ring in the centre of the hoop. 
A horizontal section of the receiver H appears therein. . 
Fig. 5, shows a section of one of the gas lamps. The space 
between the outer tube T and the inner tube V , is to be filled 
with gas supplied by the pipe R, shown in fig. 1, where a stop 
cock is inserted for adjusting the flame, which gas passes 
through a number of small holes made in the outer edge of a 
circular plate shown at fig. 6, which unites the tubes T and V 
at their tops. V is the inner tube which conveys the atmosphe- 
ric air into the centre of the flame : the upper part of this tube 
is made conical, or widening outwards, to join a circular plate 
with holes in it, a horizontal view of which is shewn at fig. 6„ 
W is a button, which can be placed at a small distance above the 
mouth of the lamp, and its use is to convey, in an expanded man- 
ner, all the air which rises through this tube to the inner surface 
of the flame, which assists the combustion very much ; this but- 
ton may be set in any convenient distance above the tubes of the 
lamp, as it slides in the cross bars X X, by which it is supported 
in the inner tube. 
A current of air also passes between the glass tube or chimney 
and the outer tube T, through holes made in the bottom of the 
glass holder, as in Argand’s lamps : this surrounds the flame, and 
completes its combustion, as explained by the view, fig. 3, and 
