Note 173 — LETTERS ON SCIENCE.

This and the following sentences allude to parts of the above-mentioned scheme. “The whole question,” wrote Mr. Jukes, “depends on the relative dates of production of the lithological composition, the petro-logical structure, and the form of the surface,” The scheme then attempts to sketch the “order of the processes which formed these three things,” in ten articles, of which the following are specially referred to by Mr. Ruskin: “1. The formation of a great series of stratified rocks on the bed of a sea.... 3. The possible intrusion of great masses of granitic rock” in more or less fluent state; and 6, 7, 8, 9, which dealt with alternate elevation and depression, of which there might be “even more than one repetition.”