ations It commences in A B
C fashion as follows: "Electric machines convert mechanical into
electrical energy.... The ratio of yield to consumption is the
expression of the efficiency of the machine.... How many foot-pounds
of electricity can be got out of 100 foot-pounds of mechanical energy?
Certainly not more than 100: certainly less.... The facts and laws
of physics, with the assistance of mathematical logic, never fail to
furnish precious answers to such questions."

The would-be critic then goes on to tabulate tests of certain other
dynamo machines by a committee of the Franklin Institute in 1879, the
results of which showed that these machines returned about 50 per cent.
of the applied mechanical energy, ingenuously remarking: "Why is it that
when we have produced the electricity, half of it must slip away? Some
persons will be content if they are told simply that it is a way which
electricity has of behaving. But there is a satisfactory rational
explanation which I believe can be made plain to persons of ordinary
intelligence. It ought to be known to all those who are making or using
machines. I am grieved to observe that many persons who talk and write
glibly about electricity do not understand it; some even ignore or deny
the fact to be explained."

Here follows HIS explanation, after which he goes on to say: "At this
point plausibly comes in a suggestion that the internal part of the
circuit be made very small and the external part very large. Why
not (say) make the internal part 1 and the external 9, thus saving
nine-tenths and losing only one-tenth? Unfortunately, the suggestion is
not practical; a fallacy is concealed in it."

He then goes on to prove his case mathematically, to his own
satisfaction, following it sadly by condoling with and a warning to
Edison: "But about Edison's electric generator! . . . No one capable of
making the improvements in the telegraph and telephone, for which we are
indebted to Mr. Edison, could be other than an accomplished electrician.
His reputation as a scientist, indeed, is smirched by the newspaper
exaggerations, and no doubt he will be more careful in future. But there
is a danger nearer home, indeed, among his own friends and in his very
household.

". . . The writer of page 242" (the original article) "is probably a
friend of Mr. Edison, but possibly, alas! a wicked partner. Why does
he say such things as these? 'Mr. Edison claims that he realizes 90
per cent. of