The purpose of this thesis is to study the theory of hyperbolas of triangles.

本论文是在研究三角形的双曲线的理论。

Now according to Newtonian theory, some of them moved in hyperbolas or parabolas never to return;

现在，牛顿理论认为，有一些彗星沿双曲线或抛物线运行，永远不再返回；

Now according to Newtonian theory, some of them moved in hyperbolas or parabolas never to return; others moved in ordinary ellipses.

现在，牛顿理论认为，有一些彗星沿双曲线或抛物线运行，永远不再返回；另外一些彗星沿普通的椭圆轨道运行。