The
first known Vacheron Constantin chronograph wristwatch was made in 1914, just
as it was becoming fashionable to place one’s watch on the wrist and
not in the pocket. That first wristwatch was a 13’’’, single
pushbutton chronograph with a beautiful enamel dial, whose 30-minute register
was placed on the dial along the axis of the 3 and the 9, (today in the Vacheron
Constantin Museum, Inventory No. 10643).
Until the late 1920s, the chronograph’s
three functions were controlled by one pushbutton on the band or coaxial with
the crown (this system had already been used in pocket watches). The drawback
of this type of single pushbutton was that the three functions ("start",
"stop", and "return to zero"), cannot be separately operated.
It was therefore not possible to put the chronograph into action after having
stopped it, without returning to zero.
By the early 1930s, Vacheron Constantin was offering
two-button chronographs, with one pushbutton controlling the return to zero
function and the other the start and stop functions. This system afforded
the advantage that after stopping the chronograph it was no longer necessary
to return to zero before activating the chronograph again, to enter an additional
timing. The Vacheron Constantin archives record the production of five split-second
chronographs during this same period. The split-seconds chronograph allows
the user to time two separate events that have begun simultaneously but are
of different durations.
The
various types of scales that appear on chronograph dials:
Division of the chronograph
seconds into 1/5th of a second
Tachometric scale
(échelle tachymétrique), which allows one to measure the speed
of a moving body over a known distance (with a base of 1'000, 200, 100, or
one mile.)
Telemetric scale (échelle
télémétrique), which allows one to determine the distance
that separates the observer from a phenomenon which is both visible and audible
(speed of sound as it travels through air, approximately 340 m/sec.)
Pulsometric scale (échelle
pulsométrique), which allows one to calculate the number of pulses
per minute (scale: 30 – 20 - 15 pulses)
Respiration scale (échelle
asthmométrique), which allows one to calculate the number of breaths
per minute (scale: 15 – 20 – 25 breaths)
Productometric scale (échelle
productométrique), which allows one to calculate the rate of serial
production per hour, as long as the unit is no smaller than 60 seconds
Multiple scale dials feature
various combinations of scales, the most common one being: pulsometer/telemeter/tachometer
For Vacheron Constantin, as for
Patek Philippe, the reference number refers only
to the shape and size of the case.
