Producer of the National Gas Engine Company. 163 
uniform diameter ; special firebricks are used, and they are 
separated from the casing by a thin layer of slag wool. The 
internal portion of the vaporiser is a ribbed casting marked A 
and is bolted to the furnace casing. The outside casing of the 
vaporiser, marked B, is also bolted to the furnace casing, but 
can be removed without disturbing the vaporiser. When both 
are removed the firebrick lining is quite easily reached, and 
the bricklayer should therefore have no difficulty in making 
good joints between the various sections of the firebrick. The 
cover marked C in Fig. 2 carries the distilling bell and the 
FIG. 2— National Gas Engine Co., Ltd. Gas Producer and Scrubber. 
hopper, and is secured to both A and B. By breaking this joint 
the condition both of the furnace and of the vaporiser can 
be readily examined. This arrangement of the vaporiser is 
well calculated for dealing with hard water. The vaporising 
water drips into a funnel marked “ water feed,” whence it is 
conducted into a “Field” 1 tube H, where it is heated by the 
hot gases, after which it is led to the “feed to vaporiser” 
1 That is, an arrangement consisting of two concentric tubes — the outer one 
being closed at the bottom, and the inner one discharging close to the bottom 
of the outer tube. 
M 2 
