ement was received. It would be ungracious to reprint here
any of the early statements of incredulity which found their way into
print, especially in Germany. But the first note of welcome came from
Simon Newcomb, in the same number of the _Astronomical Journal_ as the
paper just dealt with, and the following extract will indicate both the
difficulties felt in receiving Mr. Chandler's results and the way in which
Newcomb struck at the root of them.

[Sidenote: Newcomb's explanation.]

"Mr. Chandler's remarkable discovery, that the apparent variations in
terrestrial latitudes may be accounted for by supposing a revolution
of the axis of rotation of the earth around that of figure, in a
period of 427 days, is in such disaccord with the received theory of
the earth's rotation that at first I was disposed to doubt its
possibility. But I am now able to point out a _vera causa_ which
affords a complete explanation of this period. Up to the present time
the treatment of this subject has been this: The ratio of the moment
of inertia of the earth around its principal axis to the mean of the
other two principal moments, admits of very accurate determination
from the amount of precession and nutation. This ratio involves what
we might call, in a general way, the solid ellipticity of the earth,
or the ellipticity of a homogeneous spheroid having the same moments
of inertia as the earth.

"When the differential equations of the earth's rotation are
integrated, there appear two arbitrary constants, representing the
position of any assigned epoch of the axis of rotation relative to
that of figure. Theory then shows that the axis of rotation will
revolve round that of figure, in a period of 306 days, and in a
direction from west toward east. The attempts to determine the value
of these constants have seemed to show that both are zero, or that
the axes of rotation and figure are coincident. Several years since,
Sir William Thomson published the result of a brief computation from
the Washington Prime-Vertical observations of [alpha] Lyrae which I
made at his request and which showed a coefficient 0".05. This
coefficient did not exceed the possible error of the result; I
therefore regarded it as unreal.

[Sidenote: The forgotten assumption.]

"The question now arises whether Mr. Chandler