The Earth's Shifting Crust by Charles Hapgood - wire of information

CAMPBELL'S MECHANISM 353
ment suggested by Campbell. We have considered these ob-
jections, and they do not appear formidable. I am summarizing
some of these in the following pages, in order that the
reader may know, if any of these have occurred to him, that
they have already been given consideration.
a. The question of friction with the subcrustal layer. It
may at first appear that friction would be a powerful brake
on any extensive displacement of the crust, and unquestion-
ably
factors that could aid a displacement. A leading considera-
it would have an effect. Yet there are several mechanical
tion is that the suggested movement is a gliding motion.
Gliding is the most economical form of motion. It has been
said, in fact, that gliding constitutes an ideal form of motion
that utilizes 100 per cent of energy, as opposed to the sphere
and the cylinder, which, being round, lose 30 per cent of
their energy in rotation, which reduces their speed consider-
ably. Frankland has suggested that a rise of temperature at
the interface of the crust and the lower layer, as the result
of friction, could facilitate a displacement. Campbell considers
that the underlayer, or asthenosphere, would act more
like a lubricant than a retardant. He compares the movement
to the motion of ice floes: ". . . Observe how vast fields of
ice are started in motion just by the friction of the wind on
the surface of the ice. . . . Again, you will see the same
ice. You will
thing by visiting a pond where they are cutting
see men pushing around blocks of ice of three or four hun-
dred square feet with the greatest ease as long as the ice is
floating
in the water. . . ."
b. The question of the extent of the displacement. It has
been questioned whether a displacement of the crust might
not terminate at an early stage because of the melting of
the icecap as it moves into lower latitudes. Campbell, how-
ever, has pointed out that as the icecap moves equatorward
from a polar region, the ice will continue to accumulate on
the rear or poleward side, and that this will have the effect
of prolonging the motion of the crust. In some circumstances,
if the icecap happened to be situated on a very large land