LOSS OF POWER BY RADIATION OF HEAT.[3]


[Illustration: The Martyrs Column, Naples, Italy.]

To him who holds the purse and pays for the coal consumed, it is of
importance that between the energy of the burning fuel and the power
developed by the engine there should be the least possible loss. Every
unit of heat radiated by boiler-pipe, cylinder or heater is absolute
loss, and must come out of that purse. In an electrical plant this
matter is of great importance. There is less opportunity to have results
obscured. There is, proportionally, a large possible loss between the
coal on the grate and the far end of the cylinder, and this loss should
be reduced to the minimum. Is it not always the best economy to throw
away as little as possible, to save from waste _all_ that can be saved?
Is not the very _reason far being_, of the architect, the mechanical
engineer, in fact of every man who is paid for his advice and direction,
just this: that he shall bring to bear upon the subject, and impart to
his client honest knowledge concerning the various matters about which
he is consulted? That he shall keep abreast of the tide of discovery and
improvement, and that upon these subjects he shall _know_, not trusting
to mere hearsay or to unintelligent prejudice for his impressions.

Some little time since a gentleman from a neighboring city called upon
me for information upon the subject of coverings in general and their
comparative values. Being an intelligent man he said frankly at the