THE PHYSICAL CAUSE OF THE MOTION OF GLACIERS.—THEORIES OF
GLACIER-MOTION.
Why the Question of Glacier-motion has been found to be so
difficult.—The Regelation Theory.—It accounts for the
Continuity of a Glacier, but not for its Motion.—Gravitation
proved by Canon Moseley insufficient to shear the Ice
of a Glacier.—Mr. Matthew’s Experiment.—No Parallel
between the bending of an Ice Plank and the shearing
of a Glacier.—Mr. Ball’s Objection to Canon Moseley’s
Experiment.—Canon Moseley’s Method of determining the Unit
of Shear.—Defect of Method.—Motion of a Glacier in some
Way dependent on Heat.—Canon Moseley’s Theory.—Objections
to his Theory.—Professor James Thomson’s Theory.—This
Theory fails to explain Glacier-motion.—De Saussure and
Hopkins’s “Sliding” Theories.—M. Charpentier’s “Dilatation”
Theory.—Important Element in the Theory 495