Then **OJ** trisects the given angle.

If 0 be the degree of an invariant j - aj aj a; **oj** =a ° a a o +al aa l +...

The spherical A isosceles triangles AJB, BJC are con gruent, and we see that AB can be brought into the position BC by a rotation about the axis **OJ** through an FIG.

The axis of resultant angular momentum is therefore normal to the tangent plane at J, and does not coincide with **OJ** unless the latter be a principal axis.

HOMER' ("**Oj**,cnpos), the great epic poet of Greece.

Then with centre 0 1 and radius **OJ**, =OA 1, describe an arc. By reflecting the two arcs thus described over the centre the ellipse is approximately described.