The theory of isostasy is widely favored as an explanation of recent uplifts in the glaciated tracts of North America and Europe. If the earth’s crust sinks after a heavy, extensive load of ice is put on it, and rises after that ice melts; if the crust so behaves each time that one and the same region is glaciated and deglaciated; if similar behavior were proved in separate areas—eastern Canada, the British Isles, Scandinavia, British Columbia, Patagonia, and Antarctica—the theory would almost become certainty. As a matter of fact, field studies have been largely confined to but three of the greater ice-cap areas and in each case to uplift following the latest deglaciation. Complete testing of the isostatic theory after the manner described is evidently much more difficult than the partial test so far applied.
The sinking under load is in small part due. to purely elastic compression, . . .