C >3° 3 
The Manner in which the Motion is communi- 
cated to the Pendulum at Reft, I conceive to be thus : 
As the Pendulums are very heavy, when either of 
them is fet a going, it occalions by its Vibrations a 
very fmall Motion, not only in the Cafe the Clock is 
fixed in, but, in a greater or leflcr Degree, in every 
thing it touches; and .this Motion is communicated 
to the other Clock, by means of the Rail, againft 
which both the Cafes bear. The Motion thus com- 
municated, which is too fmall to be difcovered but 
by means of fome fuch-like Experiments as thefe, 
will, I doubt nor, be judged by many, infufficient 
to make fo heavy a Pendulum defcribe an Arch of 
two Degrees, or large enough to fet the Work a go- 
ing; and indeed it would be fo, but for the very 
great Freedom with which the Pendulum is made to 
move, atifing from the Manner in which it is hung. 
This appears from the very fmall Weight required to 
keep it going, which, when the Clock was firft put 
together, was little more than one ib. And if the 
Weight was taken off, and the Pendulum made to 
fwingtwo Degrees, it would make 1200 Vibrations 
before it decreafed half a Degree, fo that it would 
not lofe the -y 5 ob an Inch in each Vibration. 
Indeed if the Weight was hung on, the Fridion 
would be increafed, and the Pendulum would not 
move quite fo freely ; but evem in that Cafe it was 
found to lofe but little more than the part of 
an Inch, or about three Seconds of a Degree, in one 
Vibration; and therefore if the Motion communi- 
cated to it from the other, will make it defcribe an 
Arch exceeding three Seconds, the Vibrations muft 
continually increafe till the Work is fet a going. 
And 
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