"Airy R. Bean" wrote in message
...
I commend to you the works of Britten (and subsequent editors)
and Gazely. Hasluck does not, to my memory, discuss them.

Perhaps you are confusing the remontoire with the Tourbillion?


Not at all, two quite different solutions to two quite different problems.

remontoi A mechanism that compensates for the variation in the force
exerted by the mainspring as it "unwinds". Harrison's solution was to have
another' secondary, spring that was kept in a (very near) constant state of
wind by the main spring. This secondary spring provided a near constant
impetus to the oscillating element. An automatic watch achieves much the
same but more simply- it keeps the mainspring under (near) constant tension.

tourbillion: a mechanism to prevent changes in local gravity (due to
movement) from changing the period of oscillation. Not generally required in
a stationary clock and, even in watches, usually avoided by setting an
average rate in six positions.