There are various advantages attending this system of firing gas
retorts. First of all, there is already a saving of fuel to the extent
of one-half, and not unlikely there will soon be a further very decided
increase in the saving of fuel to record, inasmuch as it has been
experimentally determined within the past two or three weeks that, by
increasing its diameter to 3 ft. 4 in., one producer can be made to
provide a sufficient amount of gaseous fuel to fire two sets of eight
retorts. By the arrangement just hinted at the relative amount of fuel
used will be still further reduced. Then, again, an additional retort
can well be placed in each oven, as it occupies the position of the fire
in ordinary settings. In the third place, by the greater heat which is
obtained, the charges can be more rapidly distilled; or heavier charges
can be carbonized in a given space of time. When all the gains are put
together, the amount of coal carbonized is increased by about 40 per
cent. over any specified time. Of course, in the new or regenerator
settings there is much greater regularity of heat; and as the gaseous
fuel is perfectly free from all solid matter, and burns without any
trace of smoke, there is a total absence of deposit on the outside of
the retorts. From these two circumstances combined it is but natural to
expect that there should be greater durability of the retorts--which
is really the case. Another advantage is that, as the fuel used in
the furnaces is wholly gaseous, choking of the flues cannot by any
possibility arise. It is the confident opinion of Mr. Foulis that the
system in question can be applied with advantage to all sizes of gas
works, and that it is certainly well adapted for all works where the
summer consumption of gas is sufficiently large to give employment to
eight retorts.

As this is the first instance of the new form of gas producer and