14 MAY 1921, Page 23

When Tennyson wrote in In Memoriam :— " The hills

are shadows, and they flow From form to form, and nothing stands ;

They melt like mists, the solid lands,

Like clouds they shape themselves and go "-

he was not merely borrowing from Heraolitus, but was 'anticipating the new theory of "The Circulation of the Earth's

Crust," which is expounded by Colonel Tandy of the Survey of India in the Geographical Journal for May. Colonel Tandy repudiates our " crude natural bias " in favour of the belief that the earth's crust is inert and rigid, and he makes out a

very plausible case for the assumption that the earth's crust is extremely mobile, under the combined influences of pressure and heat.