K HI. OF NATURAL PHILOSOPHY. 409 So thut the theory agrees with the phenomena ; for the planets are more heated by the sun's rays towards their equators, and therefore are a lit fie more condensed by that heat than towards their poles. Moreover, that there is a diminution of gravity occasioned by the diur nal rotation of the earth, and therefore the earth rises higher there than it does at the poles (supposing that its matter is uniformly dense), will ap pear by the experiments of pendulums related under the following Propo sition. PROPOSITION XX. PROBLEM IV. To find and compare together the weights of bodies in the different re gions of our earth. Because the weights of the unequal legs of the canal of water ACQqca are equal ; and the weights of the parts proportional to the whole legs, and alike situated in them, are one to another as the weights of the P