Neptune's orbit is more nearly circular than that of any of the major planets except Venus. Its distance is thirty times that of the earth from the sun instead of thirty-nine times, as Bode's Law would require. That generalization was a presupposition of the calculations leading to the discovery. It was then rejected like a discredited ladder. Man's conception of the universe is widened at the thought that the outmost known planet of our solar system is about 2,796,000,000 miles from the sun and requires about 165 years for one revolution.
Professor Peirce, of Harvard University, pointing to the difference between the calculations of Leverrier and the facts, put forward the view that the discovery made by Galle must be regarded as a happy accident. This view, however, has not been sustained.
Sir Robert Ball, Neptune's Jubilee Year, _Scientific American_, Supplement, Oct. 10, 1896.
Sir Robert Ball, _The Story of the Heavens_, chap. XV.
B. A. Gould, _Report on the History of the Discovery of Neptune, Smithsonian Contributions to Knowledge_, 1850.
Robert Grant, _History of Physical Astronomy_.
Benjamin Peirce, _Proceedings of the American Academy of Arts and Sciences_, vol. I, pp. 57-68, 144, 285, 338-41, etc.
[3] See article "Neptune," _Encyc. Brit._
SCIENCE AND TRAVEL--THE VOYAGE OF THE BEAGLE
Sir Charles Lyell, in his _Principles of Geology_, the first edition of which appeared in 1830-1833, says: "If it be true that delivery be the first, second, and third requisite in a popular orator, it is no less certain that travel is of first, second, and third importance to those who desire to originate just and comprehensive views concerning the structure of our globe." The value of travel to science in general might very well be illustrated by Lyell's own career, his study of the mountainous regions of France, his calculation of the recession of Niagara Falls and of the sedimentary deposits of the Mississippi, his observations of the coal formations of Nova Scotia, and of the composition of the Great Dismal Swamp of Virginia--suggestive of the organic origin of the carboniferous rocks.
Although it is not with Lyell that we have here principally to deal, it is not irrelevant to say that the main purpose of his work was to show that all past changes in the earth's crust are referable to causes now in operation. Differing from Hutton as to the part played in those changes by subterranean heat, Lyell agreed with his forerunner in ascribing geological transformations to "the slow agency of existing causes." He was, in fact, the leader of the uniformitarians and opposed those geologists who held that the contemporary state of the earth's crust was owing to a series of catastrophes, stupendous exhibitions of natural force to which recent history offered no parallel. Also enlightened as to the significance of organic remains in stratified rock, Lyell in 1830 felt the need of further knowledge in reference to the relation of the plants and animals represented in the fossils to the fauna and flora now existing.