CHAPTER II.
THE CYLINDER ESCAPEMENT.
There is always in mechanical matters an underlying combination of
principles and relations of parts known as "theory." We often hear the
remark made that such a thing may be all right in theory, but will not
work in practice. This statement has no foundation in fact. If a given
mechanical device accords strictly with theory, it will come out all
right practically. _Mental conceptions_ of a machine are what we may
term their theoretical existence.
When we make drawings of a machine mentally conceived, we commence its
mechanical construction, and if we make such drawings to scale, and add
a specification stating the materials to be employed, we leave only the
merest mechanical details to be carried out; the brain work is done and
only finger work remains to be executed.
With these preliminary remarks we will take up the consideration of the
cylinder escapement invented by Robert Graham about the year 1720. It is
one of the two so-called frictional rest dead-beat escapements which
have come into popular use, the other being the duplex.
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