220 Description of an Apparatus, &c. 



The pure gas enters the tube 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 gazometer 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 gazometer K at the part M, with its stays or arms, and 

 the manner in which the iron pipe C, before described at 

 fig. 1, sliding on 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 7?, 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 Tand V-aX their tops. V\§ the inner tube which 

 conveys the atmospheric air into the centre of the flame ; 

 the upper part of this tube is made conical, or widening ouU 

 wards, to join a circular plate with holes rn it, a horizontal 

 view of which is shown at fig. 6. IV 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 manner, all 

 the air which rises through this tube to the inner surface of 

 the flame, which assists the combustion very much ; this 

 button may be set at any convenient distance above the tube* 

 of the lamp, as it slides in the cross bars XX, by which it 

 is supported in the inner tube. 



A current of air also passes between the glass tube or chim- 

 ney 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 section, fig. 4, which have a glass 

 upon each. ZZZZ, figs. 3, 4, 5, and 6, show the tube 

 through which the lamp is supplied with gas from the pipe 

 R, fig. 1. 



XXXVIII. Re- 



