On the Procession of a Viscous Spheroid in Nature, Volume 18, 1878, pp. 580-582 [LEATHER BOUND. GEORGE DARWIN'S FISSION THEORY OF THE FORMATION OF THE MOON]

London: Macmillan, 1878. 1st Edition. FIRST EDITION OF GEORGE DARWIN'S FISSION THEORY OF THE FORMATION OF THE MOON. The history of modern lunar origin theory dates to this paper. A reprint of this paper was published in the 1879 Philosophical Transactions; that paper is sometimes misidentified as a first edition, but it is not. This paper, the one appearing in 1878 in Nature is the true first.

"Before Kuiper revived the double planet thesis, George Darwin, son of the famous British naturalist, had in 1878 advanced an attractive alternative. Drawing on the pronounced tidal effects exerted between the earth and moon, Darwin speculated that the moon's mass had been ejected from a fluid and rapidly spinning protoearth when centrifugal force and solar tides, acting on matter in the earth's equatorial plane, exceeded the force of gravity. In time, the moon moved out to its present orbit and attained its coincident period of rotation and revolution as a result of tidal interactions between the two bodies. 

Darwin proposed that these tidal effects on the spherical shape of the earth have changed as the moon has moved farther away in its orbit. Darwin's proposed idea for the creation of the moon came to be known as the "fission theory" of lunar formation. This theory basically stated that the moon broke away from the earth due to its rapid rotation. From this he also calculated that it would have taken at least 56 million years for the moon to reach its current distance from the earth" (Giedd, Tidal Friction).

Darwin argues "that tides raised by the Moon imply an Earth much closer to the Moon far in the past. Modeling Earth (and Moon) as a viscous liquid rather than a system dominated by oceans and basins, Darwin calculated that the two bodies merged about 50 million years ago, with the system rotating every five hours" (Crottis, The New Moon, 159). CONDITION & DETAILS: London: Macmillan. 4to. (11 x 8.25 inches; 275 x 206mm). Ex-libris bearing only minimal markings - a few stamps on the title page and none whatsoever on the spine. Full volume. Handsomely and professionally rebound in half leather. 5 raised bands at the spine, gilt-ruled. One red morocco label; one black morocco label; both gilt-lettered. Tightly and very solidly bound. Clean and bright throughout. Very good + condition.