HUBERT SARTON, PIONEER OF THE "ROTOR" MECHANISM
(3) IN AUTOMATIC WATCHES
automatic mechanism, like the pallet, hairspring, etc., is one
of the factors contributing to the stature of watchmaking today.
It is impossible to measure the extent to which this automatic
mechanism has generated employment and profit.
So do we know at least where it comes from, and who invented
I will endeavour to tell you, hoping to open the debate, as
the subject is delicate, and unfortunately calls into question
a school of thought which is very widely accepted. However,
if history has caught up with us, we cannot escape its verdict;
I am simply its vehicle.
At present, no one can say who originated the principle, but
I am nevertheless going to pinpoint the origin of the rotor
mechanism, which I am not linking to the origin of the principle
There is a well-known book which is an authority on automatic
watches, by Alfred Chapuis and Eugène Jaquet, published in 1952
by Editions Griffon of Neuchâtel (4).
This book of over 200 pages dedicates 35 of those pages to Abraham
Louis Perrelet, primarily to attribute to him the rotor mechanism
mentioned above. In the long list of individuals who have contributed
to the development of the automatic watch, there is a name that
is missing: that of Hubert Sarton (1748-1828), a watchmaker
from Liège (5). My analysis puts him in prime position.
History often catches up with us and, since 1993, for me, one
event has followed inevitably upon another. In March, a manuscript
report originating from the Académie des Sciences de Paris came
into my possession, and in April, the watch attributed to Perrelet
by Chapuis was put on sale at Antiquorum (6). The report is
a manuscript describing a mechanism. Detailed analysis of the
manuscript revealed that this mechanism is the one that is now
called "automatic rotor movement." (3)
As this mechanism had been attributed to Perrelet in 1952, I
set off in search of the factors that had caused Chapuis to
make this attribution. I found nothing, despite hundreds of
various contacts, e-mails and letters.
I have deduced today that Alfred Chapuis made a mistake.
Unfortunately, this mistake has become firmly entrenched and
has been repeated many times since, but always without supporting
We must put things in their proper place.
Here, therefore, are some factors (amongst many others), which
show that the watch invented by H. Sarton is indeed identical
to the one too rashly attributed to Perrelet. Several details
For example the fusees of these pieces (7) - that of the report
and that attributed to Perrelet - are absolutely identical,
even in the gear ratios. This view of the fusee and the internal
gear, the teeth of which are turned towards the centre and of
which there are 30, as in the text, proves this (8).
The differential gear, also housed in the centre of this fusee,
is absolutely identical (9). Then there are the reversers (10).
Locking of the weight when the watch is fully wound (11), etc.
History will reveal the truth sooner or later.
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