Climate and Time in Their Geological Relations A Theory of Secular Changes of the Earth's Climate
CHAPTER XXX.
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