minus declination."

* * * * *

"Precisely, at the winter solstice. Now to explain what is happening.
The year went normally until June twenty-first. That day was of the
correct length, about fourteen hours and fifty minutes long. The
twenty-second should have been shorter. Instead, it was longer than the
twenty-first. Each day, instead of getting shorter as it should at this
time of year, is getting longer. We have already gained some thirty-two
minutes of sunlight at this latitude. The explanation is that the angle
between the equator and the elliptic is no longer 23-1/2 deg. as it has
been from time immemorial, but it is greater. If the continuing tilt
keeps up long enough, the obliquity will be 90 deg. When that happens,
there will be perpetual midday at the north pole and perpetual night at
the south pole. The whole northern hemisphere will be bathed in a
continuous flood of sunlight while the southern hemisphere will be a
region of cold and dark. The condition of the earth will resemble that
of Mercury where the same face of the planet is continually facing the
sun."

"I understand that all right, but I am still in the dark as to what is
causing this increase of tilt."

"No more than I am, old dear. Herriott keeps babbling about a hidden
body which is drawing the earth from its normal axial rotation, but the
fool ignores the fact that a body of a size sufficient to disturb the
earth would throw every motion of the solar system into a state of
chaos. Nothing of the sort has happened. Ergo, no external force is
causing it. I am positive that the force which is doing the work is
located on the earth itself. Furthermore, unless my calculations are
badly off, this force is located on or very near the surface of the
earth at approximately the sixty-fifth degree of north latitude."

"How can you tell that, Doctor?"

"It would take me too long to explain, Carnes. I will, however, qualify
my statement a little. Either a variable force is being used or else a
constant force located where I have said. The sixty-fifth parallel is a
long line. The exact location and the nature of that force, we have to
find. If it be man-made, and I'll bet my bottom dollar that it is, we
will also have to destroy it. If we fail, we'll see this world plunged
into such a riot of war and bloodshed as has never before been known. It
will be literally a fight of mankind for a place in the sun. Due to its
favor