A great deal of Miller's work was done for _The Witness_. He was a most conscientious as well as a most able journalist, and he brought to his occupation a rare literary power. There was an imaginative and poetic strain in his nature which sometimes showed itself in the weaker form of fine writing, but often gave eloquence to his descriptions and fervour to his argument. This is the living part of him; for it is certainly not their scientific value that causes Hugh Miller's books to be still read. Miller's most important works are _The Old Red Sandstone_ (1841), _Footprints of the Creator_ (1847), _My Schools and Schoolmasters_ (1854), and _The Testimony of the Rocks_ (1857). In their geological aspect they merely supply the raw material of science. Miller had not the previous training requisite to give his work the highest value. He knew little or nothing about comparative anatomy, and therefore could not himself deal with the fossils he discovered. In the view of modern experts his scientific value lies in his strong common sense and his keen powers of observation amounting almost to genius. His function is to stimulate others rather than to sway thought by great discoveries. A liberal in politics, he was something of a conservative in science. _The Footprints of the Creator_ was written in answer to the _Vestiges of Creation_, and its author figures as one of the numerous reconcilers of the text of Genesis with the discoveries of geology. His value in literature is higher than in science, for he wrote a style always pleasant, and sometimes eloquent. _My Schools and Schoolmasters_, a volume of autobiography, is one of the best of its class in the language, and is the work by which Miller will be longest remembered. Related to geology, and even more influential upon modern thought, has been the theory of biological evolution, represented within the present period by Robert Chambers, Charles Darwin and Alfred Russel Wallace. Thomas Huxley too, though so much of his work is of a later date, demands mention for his long polemic on behalf of evolution, begun immediately after the publication of _The Origin of Species_ and continued till his death. The work of Sir Richard Owen the great anatomist had an important bearing upon this theory, but he was neither a Darwinian nor are his scientific writings literature. [Sidenote: Robert Chambers (1802-1871).]