further light, for it is certain from his result that the earth cannot be a rigid body. It is quite true that, even though the earth were rigid, the Pole might revolve in a circle, and that circle might have a thirty-feet radius, but in such a case the period would be only about three-quarters of the 427 days which he has found. In the interest, therefore, of the theoretical astronomer, as well as on the other grounds which I have set forth, Mr. Chandler's investigations must be regarded as a most important contribution to modern astronomy.