ions as to type
of engine, profile of line, and load of train. Two sets of comparative
trials were made, both of them in winter. The three engines used were some
of those built by Schneider. In comparison with anthracite, the economy in
favor of petroleum refuse was 41 per cent. in weight, and 55 per cent. in
cost. With bituminous coal there was a difference of 49 per cent. in favor
of petroleum as to weight and 61 per cent. as to cost. As compared with
wood petroleum was 50 per cent. cheaper. At a speed of fourteen miles an
hour up an incline of 1 in 125 the steam pressure was easily kept up at 9
to 91/2 atm. with a No. 9 injector feeding the boiler all the time.

Up to the present time the author has altered seventy-two locomotives to
burn petroleum; and from his own personal observations made on the foot
plate with considerable frost he is satisfied that no other fuel can
compare with petroleum either for locomotives or for other purposes. In
illustration of its safety in case of accident, a photograph was exhibited
of an accident that occurred on the author's line on 30th December, 1883,
when a locomotive fired with petroleum ran down the side of an embankment,
taking the train after it; no explosion or conflagration of any kind took
place under such trying circumstances, thus affording some proof of the
safety of the petroleum refuse in this mode of firing. Although it is
scarcely possible that petroleum firing will ever be of use for
locomotives on the ordinary railways of coal-bearing England, yet the
author is convinced chat, even in such a country, its employment would be
an enormous boon on underground lines.

* * * * *

CHARCOAL KILNS.

[Illustration: KILN FOR BURNING CHARCOAL.]

In answer to the inquiry of a correspondent about charcoal making, we
offer two illustrations that show a method of manufacture differing from
that usually adopted, which is that of burning on the bare ground, and
covering with soil or sods to exclude the air. These kilns are made of
brick, one course being sufficient, bands of iron or timber framework
being added to strengthen the brickwork with greater economy. The usual
style is conical, and the size is 24 feet in diameter, with an equal
height, holding about 40 cords of wood. The difference in price is 1-1/8
d. per bushel in favor of these kilns as compared with the usual mounds,
the burner being furnished with the use of the kilns, and