The Redwood gazette. [volume] (Redwood Falls, Minn.) 1873-1940, 1878-11-28
AMERICAN DISPLAY AT THE
PARIS EXPOSITION.
Wonders OF the Mechanical Depart.
ment.

Wonders OF the Mechanical Depart.
ment.
From the London Times. Aug. 2.]
Perhaps, however, the most Inn
portant display in this department, all things
considered, is that of the Waltham Watch
tions. The readers of the Times reports of
the Philadelphia Exhibition will not need to
be informed Of the admirable machinery by
which the works of the Waltham watches are
produced, or their singular exactitude. which
enables any part Of a watch to be replaced by
the corresponding. piece Of any other watch OF
the same grade. In this mechanical produce
ton of machines, America has long led the
world. and the mechanism by which the En-
glish army rifle is still produced is with i'm
material notifications contribution from
the American armOries. But in the Waltham
works science has been brought to the
aid Of native ingenuity to such degree that
even since the Philadelphia Exhibition the
fabrication of watches has gone through
large arc OF another revolution. What was
begun by applying such machines that their
work was beyond competition on anything
like equal terms from any hand-work is con-
tinued by the construction Of the most essen
tial parts OF q watch ON a new principle, which
permits an approach to perfection unattain-
able by the old mechanism, however pro-
duccd. Every one knows that the great diff
Guilty in making thermometers has teen the
contraction due to change of temperature;
but what is less well known is that this diff
Guilty is due less to the balance, which, by its
construction with bi-segmentai rim (of brass
and stceD, may be perfectly corrected, than
to the expansion OF the balance or hair
spring, which, being immensely longer, causes
live times the error caused by the expansion
or contraction balance wheel alone. The
two pieces must be considered as one,
and the compensation effected in the wheel
or lin must answer for the spring as well rs
Tor Itself. The theoretical and insuperable
difficulty in this compensation has always bcen
that the error caused by the expansion and
contraction OF the spring was in a different
ratio from that OF the correcting expansion or
contraction wheel, and the two quantities may
be compared to curves with two ralii, which
could be brought together at two points, but
not to coincide throughout, SO that if the COM
pensation at the extremes Of temperature Is
correct, the mean must be in error and vice
rerSd.
The old compensation was, speaking broad
~, in brazing band Of brass on one of steel,
process both theoretically and mechanically
erroneous, since the contraction and expan-
sion can only go Oh with certain tendency to
disrupture OF the elements and consequent in
equality Of the action. The new balance pro-
ceeds on an entirely different arrangement OF
the compromising metals. The rim, of plain
steel, is cut nearly thrOuc h at the fixed cx-
trcmities OF the semi circles by several
saw-tooth shaped notches, the number de-
termined by experiment, and the brass il
forced into these notches. The compensat-
ing weights are then put on at tie other
extrcmities OF the semi-circ'cs instead OF be-
ing distributed along them empirically, and it
sfouId possible in this arrangement SO to dis
tribute the compensation and compensating
weights as to give at will compensation for
the mean Temperature, either in excess Of, or
less than the extremes, and Of course, to give
ball