of measuring Time at Sea. 57 
Article V. 
Fi ifth cause of error in watches, the little power of the 
-. regulators with regard to thew motive force. 
This inconvenience arises, according to what has been 
said aboye, from the resistance of the air, the friction of 
the suspension, &c. causing a considerable loss of motion 
in the regulator in each vibration; and since the balance of 
a watch ought to go of itself, (partir qu doigt*) as watch- 
makers say, (that is, it should be put in motion by the mo- 
tive force, when this motion has ceased from any cause what= 
ever,) this balance can only be very slight. Make the ba- 
lance of a watch vibrate separately from the wheel-work, and, 
you will see that if at first the vibration is 180° it will lose 
all its motion in 90” in a horizontal situation, and in 607 
in a vertical one; instead of which a pendulum preserves 
the oscillatory motion given to it for twelve or fifteen hours 
withont any foreign bala ; consequently the impression of 
the motive force, and the variations which arise from wear 
and from friction, are in watches, with regard to the effect 
that they paadace on the pendulum, in the proportion of 
15 hours, or 900’ to 11’. 
Paar Dirk 
Description of the new marine watch, and of the means by 
which we have avoided the different causes of irregularities 
related above. 
Article I. 
Of wheel-work. 
If the defects remarked in the construction of watches, 
are the sources whence all their irregularities are derived, in 
order to render a work of this kind capable of the greatest 
accuracy possible, it is necessary, consequently, to collect 
together the opposite properties. Thus, after having given 
to this work the greatest simplicity of which it is suscepti- 
ble, it is necessary, 
Ist, To reduce the friction to the least possible value, 
* ‘They are obliged to take this precaution, that the watch may not stop 
by the different motions which it may receive, and by the losses which it 
expericnces in its motive force from the ditliculty with which the wheel-work 
acts, and the effect produced when the hands are put to the Lour, &c. d 
an 
