firm, and myself--trials which lasted for twelve hours--that the total
consumption of fuel, including that for getting up steam from cold
water, was just under 1.8, actually 1.79 lb. per gross indicated
horse-power per hour. That gross indicated horse-power was obtained in
a manner which it is desirable should always be employed in steamboat
trials. It was not got by using as a divisor the horse-power of the
most favorable diagram obtained during the day; but it was got from
diagrams taken during the regular work; then, every half-hour, when
the pressure began to die down, from coal being no longer put upon the
fire, diagrams taken every quarter of an hour, and then toward the
last, every five minutes; and the total number of foot pounds were
calculated from these diagrams, and were used to obtain the gross
indicated horse-power.

Further, so far as could be ascertained by the process of commencing a
trial with a known fire, and closing that trial at the end of six
hours, with the fire as nearly as possible in the same condition, the
consumption was 1.66 lb. of coal per gross indicated horse-power per
hour. So that, without taking into account the coal consumed in
raising steam from cold water, the engine worked for 1-2/3 lb. of coal
per horse per hour. I think it well to give these details, because
undoubtedly it is an extremely economical result.


ETHER ENGINE.

Our president alluded to the employment of ether as a means of
utilizing the heat which escaped into the condenser, and gave some
account of what was done by Mons. Du Tremblay in this direction. It so
happened that I had occasion to investigate the matter at the time of