ts, owing to the before mentioned
stipulation having to be considered and allowed for in construction.

In answer to an inquiry I made the other day, the gentleman referred to
informed me that he has now had this setting in operation for six
months. He has three retorts, 14 by 16 inches, and 8 feet long, in an
oven carbonizing 2 cwt. of coal every four hours; the heats are higher
and more regular; and the retorts easier kept clear of carbon. The coke
drawn from the top retort is sufficient for fuel. My oven would hold
four retorts; and the same fuel would heat this number just as well as
the three. I used only the coke from Cowdenheath parrot coal for this
setting; but had to mix it with Burghlee coke for the old system of
setting.

No doubt most of you will have noticed the satisfactory results obtained
by Mr. Hack, of the Saltley Gas Works, Birmingham, and by Mr. McMinn, of
Kensal Green, with the furnaces employed by them for gaseous firing
without recuperation, whereby they are enabled to save fuel and
carbonize more coal per mouthpiece than with the old system. Still they
admit that the saving by this setting is only in fuel, with increased
production, but without any economy of labor--one of the points in favor
of regenerative setting being a saving of at least 25 per cent. in the
latter respect. Even where regenerative settings cannot be had, I think
the system of using gaseous fuel is well worthy the attention of
managers; the expense of altering the existing settings to this method
being very small.

IMPROVEMENTS IN GAS PURIFICATION.

I must now, however, pass on to some other topics. After the proper
production of the gas, we have still the processes of purification to
consider, and how this operation can best be effected at the smallest
cost, combined with efficiency and the least possible annoyance to
residents in the immediate vicinity of gas works. I think all gas
engineers are agreed that in ammoniacal liquor we have a useful and
powerful purifying agent, although each one may have his own particular
idea of how this can be most efficiently applied--some advocating
scrubbers, others washers. But these are things which each one must
determine for himself. But in whatever way it is applied, we know that
it can be profitably used for this purpose; and I am not without hope
that it may soon be found possible to remove nearly all the impurities
by this means.

At present, however, this is not so. And co