Meddelelser 2008 - Ole Rømers Venner

whether and how to sign the movement: in view of his own claims Hrytgens invenit,
Thuret fecir would not have satisfied his dignity whereas Thuret invenit & fecit would
have raked up the conflict with Huygens. Above the name plate we see the regulator
for adjusting the oscillation period of the balance.
6. Who ordered this clock?
The well-considered design as well as its refined execution strongly suggest that the
clock was made to be actually tested on board of a ship rather than merely as an
experimental construction to test the accuracy of the new invention on Thuret's
workbench or Huygens' desk. This leads immediately to the intriguing question on
whose initiative we owe the clock. There are three possibilities: (l) the clock was
ordered by Christiaan Huygens, (2) by someone else, or (3) Isaac Thuret himself took
the initiative.
In my opinion, we may consider the second pssibiliry at rather unlikely. The
complicated verification of the clock's reliability in an actual situation could not be
trusted to a ship captain but should be carried out under the direct supervision of a
scientist familiar with timekeepers and their problems. There are no indications that
someone else than Huygens might have been involved.
As the later history has confirmed, the initiative of improving the accuracy of clocks
and testing their performance was either in the hands of scientists or of clockmakers
as John Harrison (1693-1776) and John Arnold {1736-1799) in England and Pierre Le
Roy ( l7l7-17S5) and Ferdinand Berthoud (17?7-1807) in France.5e Hence, it is not
unlikely that, if not ordered by Huygens, 'Ihuret himself decided to make a large
version of a watch after the new invention, provided with the extra transmission
between balance and verge escapement recommended by Huygens but probably
never applied in pocket watches. However, this does not solve the problem of a
qualified person to test the clock. Therefore, if the clock was made by Thuret on his
own initiative, we may expect that Huygens knew about it.
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