W. Dennis on the Theory of the Tides. 241 
they will then represent the constant action o 
the same time allow the whole globe or any of its parts to move 
to a limited extent under the action of another force. By means 
three other cords with pulleys, attach three additional weights 
to the sarne points to act in the same direction and thus to rep- 
resent the added attraction of the moon; and by a proper adjust- 
ment of the second set of weights, and of the size or elastic 
force of the first set of cords, not only the increased elongation 
of the earth (the spring tides) belonging to this position of the 
other bodies, but its temporary approach to the sun, may be 
when the suspension is completed clamp the cords at the pulleys ; 
the sun and at 
. 
and in like manner does the combin 
* 
the disturbing influence of these bodies is to render the sur- 
tions not so affected, which of course at the same time sink. But 
I the case we are now considering, while the moons influence 
8 producing the lunar tide on two opposite sides of the earth, 
sun is at the same time acting upon the intermediate equa- 
