TO W. GARNETT, Esq.
Glenlair, Dalbeattie, 24th July 1877.
. . . There is a great slur over the word mechanics
since a few poets
and biologists have misused it. Pratt thought it a fine
word.
The result of motion without
reference to time
I call Displacement. Kinematics must involve the idea of time if
it
treats of continuous displacements, velocities, and accelerations,
though
it does not contain within itself materials for
comparing
different intervals of time. For this we must go to the science which
deals
with matter; call it Kinetics, Dynamics, or
Mechanics.
But I consider that Statics
also deserves a
place on the same level as Kinematics, as it deals with the
equivalence
of different systems of forces. But I do not agree with Whewell that
Statics
is more elementary than Kinematics. . .