ring the last eight or ten years.
I think the use of small gas furnaces in private workshops and
laboratories may fairly be said to have enabled the experiments on most,
if not all, of these alloys to be carried out to a successful issue.

I have been asked to say something regarding gas engines. The only thing I
can say is that I know very little about them. In my own works we have
about 300,000 cubic feet of space, all of which requires to be heated,
more or less, during the greater part of the year. For this purpose we
must have a steam boiler, and having this steam, it costs little to run it
first through the engine, and so obtain our power for a good part of the
year practically without any cost. It would not pay, under any
circumstances, to have two separate sources of power for summer and
winter; and therefore the use of gas for power has never been considered.

For irregular work and comparatively small powers, gas-engines have
special and great advantages; and in this respect they may, perhaps, class
with gas melting furnaces. If I wanted 1, or 10, or 20 lb. of melted
metal, I could melt and make the casting in less time and with less cost
than would be required to light a coke fire. There is no possible
comparison in the two, as to convenience and economy; but if I wanted to
melt 3 or 4 cwt. or 3 or 4 tons every day, I should not dream of using gas
for the purpose, as the extra cost of gas in such a case would not be
compensated by the saving in time. In commercial matters we must always
consider first what is the most profitable way of going about our work;
and, so far as I myself am concerned, I have always found it advantageous
to expend some money annually on proving this by direct experiment. It is
almost always possible to learn something, even from a failure.

I will now, with a blowpipe and small foot blower, heat a short length of
locomotive boiler tube to a brazing heat on the table; and, in conclusion,
will convert the table into a small foundry. I cannot cast you a flywheel
for a factory engine; so will try at something smaller, and will reproduce
a medallion portrait of Her Majesty, in cast iron, the original of which
is silver, commonly valued at half a crown. From the time I light the
furnace until I turn you out the finished casting I shall perhaps keep you
eight or nine minutes. I can remember in the good old times 25 years ago,
before I used gas furnaces, that it sometimes took about two hour