author to a very distinguished place among the pioneers of electric
science, and it is somewhat remarkable that they did not lead him
straight to the discovery of the "action and reaction" principle of
dynamo-electric magnetic induction to which he approached so closely,
and it is also a curious fact that so suggestive and remarkable a
paper should have been written and published as far back as 1864, and
that it should not have produced sooner than it did a revolution in
electric science.--_Engineering._

* * * * *




THE ELIAS ELECTROMOTOR.


We lately published a short description of a very interesting
apparatus which may be considered in some sense as a prototype of the
Gramme machine, although it has very considerable, indeed radical
differences, and which, moreover, was constructed for a different
purpose, the Elias machine being, in fact, an electromotor, while the
Gramme machine is, it is almost unnecessary to say, an electric
generator. This apparent resemblance makes it, however, necessary to
describe the Elias machine, and to explain the difference between it
and the Gramme. Its very early date (1842), moreover, gives it an
exceptional interest. The figures on the previous page convey an exact
idea of the model that was exhibited at the Paris Electrical
Exhibition, and which was contributed by the Ecole Polytechnique of
Delft in the Dutch Section. This model is almost identical with that