With reference to the great improbability of Laplace's original Nebular Hypothesis being true, Dr. See says, "We may calculate from the preponderance of small bodies actually found in the solar system--eight principal planets, twenty-five satellites (besides our moon), and 625 asteroids--that the chances of a nebula devoid of hydrostatic pressure producing small bodies is about 2{658} to 1, or a decillion decillion (10{66}){6} to the sixth power, to unity. This figure is so very large that we shall content ourselves with illustrating a decillion decillion, and for this purpose we avail ourselves of a method employed by ARCHIMEDES to illustrate his system of enumeration. Imagine sand so fine that 10,000 grains will be contained in the space occupied by a poppy seed, itself about the size of a pin's head; and then conceive a sphere described about our sun with a radius of 200,000 astronomical units[522] (α Centauri being at a distance of 275,000) entirely filled with this fine sand. The number of grains of sand in this sphere of the fixed stars would be a decillion decillion[523] (10{66}){6}. All these grains of sand against one is the probability that a nebula devoid of hydrostatical pressure, such as that which formed the planets and satellites, will lead to the genesis of such small bodies revolving about a greatly predominant central mass."[524] In other words, it is practically certain that the solar system was _not_ formed from a gaseous nebula in the manner originally proposed by Laplace. On the other hand, the evolution of the solar system from a rotating spiral nebula seems very probable. * * * * * Some one has said that "the world knows nothing of its greatest men." The name of Mr. George W. Hill will probably be unknown to many of my readers. But the late Prof. Simon Newcomb said of him that he "will easily rank as the greatest master of mathematical astronomy during the last quarter of the nineteenth century."[525] Of Prof. Newcomb himself--also a great master in the same subject--Sir Robert Ball says he was "the most conspicuous figure among the brilliant band of contemporary American astronomers."[526] An astronomer is supposed to say, with reference to unwelcome visitors to his observatory, "Who steals my purse steals trash; but he that filches from me my clear nights, robs me of that which not enriches him, and makes me poor indeed."[527] Cicero said, "In the heavens there is nothing fortuitous, unadvised, inconstant, or variable; all there is order, truth, reason, and constancy"; and he adds, "The creation is as plain a signal of the being of a God, as a globe, a clock, or other artificial machine, is of a man."[528] "Of all the epigrams attributed rightly or wrongly to Plato, the most famous has been expanded by Shelley into the four glorious lines--