Sir Charles Lyell in his Principles of Geology, published in 1834, remarks upon the accumulating proofs that the climate of the earth had undergone great changes in the past, and he endeavoured to show that these changes might have been produced by the varying distribution of sea and land. He says, “But if, instead of vague conjectures as to what might have been the state of the planet at the era of its creation, we fix our thoughts steadily on the connexion at present between climate and the distribution of land and sea; and if we then consider what influence former fluctuations in the physical geography of the earth must have had on superficial temperature, we may perhaps approximate to a true theory.”