Of course, these feats are quite impossible. We might as
well dream of getting 5 horse power out of a steam engine for one pound
of coal per hour.
While the chemist is busy with his researches for substances and
combinations which will yield great power with small quantities of
material, the engineer assiduously endeavors to reconvert the chemical
or electrical energy into mechanical work suitable to the various needs.
To get the maximum amount of work with a minimum amount of weight, and
least dimensions combined with the necessary strength is the province
of the mechanical engineer--it is a grand and interesting study; it
involves many factors; it is not, as in the steam engine and hydraulic
machine, a matter of pressures, tension and compression, centrifugal and
static forces, but it comprises a still larger number of factors, all
bearing a definite relation to each other.
With dynamo machines the aim has been to obtain as nearly as possible
as much electrical energy out of the machine as has been put in by the
prime mover, irrespective of the quantity of material employed in its
construction.
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