]

Elementary as these principles will appear to the modern student or
engineer, they were denounced as nothing short of absurdity at the time
of their promulgation--especially so with regard to Edison's proposal
to upset the then settled dictum that the armature resistance should
be equal to the external resistance. His proposition was derided in
the technical press of the period, both at home and abroad. As public
opinion can be best illustrated by actual quotation, we shall present a
characteristic instance.

In the Scientific American of October 18, 1879, there appeared an
illustrated article by Mr. Upton on Edison's dynamo machine, in which
Edison's views and claims were set forth. A subsequent issue contained a
somewhat acrimonious letter of criticism by a well-known maker of dynamo
machines. At the risk of being lengthy, we must quote nearly all this
letter: "I can scarcely conceive it as possible that the article on the
above subject '(Edison's Electric Generator)' in last week's Scientific
American could have been written from statements derived from Mr. Edison
himself, inasmuch as so many of the advantages claimed for the machine
described and statements of the results obtained are so manifestly
absurd as to indicate on the part of both writer and prompter a positive
want of knowledge of the electric circuit and the principles governing
the construction and operation of electric machines.

"It is not my intention to criticise the design or construction of the
machine (not because they are not open to criticism), as I am now
and have been for many years engaged in the manufacture of electric
machines, but rather to call attention to the impossibility of
obtaining the described results without destroying the doctrine of the
conservation and correlation of forces.

. . . . .

"It is stated that 'the internal resistance of the armature' of this
machine 'is only 1/2 ohm.' On this fact and the disproportion between
this resistance and that of the external circuit, the theory of the
alleged efficiency of the machine is stated to be based, for we are
informed that, 'while this generator in general principle is the same
as in the best well-known forms, still there is an all-important
difference, which is that it will convert and deliver for useful work
nearly double the number of foot-pounds that any other machine will
under like conditions.'" The writer of this critical letter then
proceeds to quote Mr. Upton'