then leaſt of all, and returns to the firſt magnitude nearly, when the body arrives at the next node. But if the nodes are ſituate at the octants after the quadratures, that is between C and A, D and B, it will appear from what was juſt now ſhewn that in the paſſage of the body P from either node to the ninetieth degree from thence, the inclination of the plane is perpetually diminiſhed; then in the paſſage through the next 45 degrees. to the next quadrature. the inclination is increaſed; and afterwards again, in its paſſage through another 45 degrees to the next node, it is diminiſhed. Therefore the inclination is more diminiſhed than increaſed, and is therefore always leſſ in the ſubſequent node than in the preceding one. And by a like reaſoning, the inclination is more increaſed than diminiſhed, when the nodes are in the other octants between A and D, B and C. The inclination therefore is the greateſt of all when the nodes are in the ſyzygies. In their paſſage from the ſyzygies to the quadratures the inclination is diminiſhed at each appulſe of the body to the nodes; and becomes leaſt of all when the nodes are in the quadratures, and the body in the ſyzygies; then it increaſes by the ſame degrees by which it decreaſed before; and when the nodes come to the next ſyzygies returns to its former magnitude.
Cor. 11. Becauſe when the nodes are in the quadratures the body P is perpetually attracted from the plane of its orbit; and becauſe this attraction is made towards S in its paſſage from the node C through the conjunction A to the node D; and to the contrary part in its paſſage from the node D through the oppoſition B to the node C;
