ground in a very simple manner, we think it will be sufficient.
Those forwarding the solutions not published will accept our thanks
and assurances that it is not because they lack merit that they are
declined.--EDS.

* * * * *

RECIPROCATING PARTS OF STEAM ENGINES.

MESSRS. EDITORS:--In one of the late numbers of your journal, you
publish a paper, read by Mr. Porter before some learned society in New
York, on something about the possibility or practicability of running
a steam engine at a high rate of speed, and claiming to give a
scientific explanation of the why and wherefore. Now, scientifically,
I know nothing about a steam engine; practically, I know how to stop
and start one. Therefore, you will understand that what I say is not
as coming from one who claims to be wise above what is written, but as
simply being a statement of the case, as it appears to one who wants
to learn, and takes this way to draw out the truth. A scientific
theory, invested with all its sines, coefficients, and other
paraphernalia, is a very pretty thing to look at, no doubt, for those
who understand it, and, when properly applied, is invaluable; but
when, as in this case, a practical question is to be decided, by the
aid of a scientific demonstration, it will not do to throw aside the
main elements of the problem, or any, in fact, of the minor points, no
matter how trivial they may appear.

Mr. Porter's labors were strictly of a scientific nature. He starts
out with the proposition that what he is about to explain is very
simple, and very likely it is; but, for one, I can't see it, and I
want more light. He says that it takes a certain number of pounds to
overcome the inertia of the reciprocating parts of a certain weight,
to give it a certain speed. What is inertia? He says, "we will not
take into account the friction of parts." Now, my understanding of
this point is, that friction is practically one of the main elements
in the problem. How can we hope to obtain a correct solution when he
rubs out one of the terms of the equation? What is friction doing all
the time, while he is theoretically having his reciprocating parts
storing up power and then giving it out again, just at the right time,
and in the right quantity?

What an immense amount of iron has been wasted by being cast into fly
wheels, when a fraction of the amount, if only put into cross heads,
would render fly wheels unnecessary!

Mr.