Drayson problem von barley alfred (2 Ergebnisse)

PAPERBACK. Zustand: cover wear otherwise good. First edition. xxivpp + 48pp octavo paper. presentation copy signed "with the author's best wishes".

Printer Wrapper. Zustand: Good. BARLEY, Alfred H. The Drayson Problem. His important astronomical discovery. 48pp. Original printed wrappers, with rust marks from the staples and small rust hole to the upper wrapper. 8vo. Exeter: Wm. Pollard. 1922. ~ Alfred Wilks Drayson (1827-1901) was an English army officer, writer and astronomer. He was a personal friend of Arthur Conan Doyle, who dedicated to him the short story collection The Captain of the Polestar. He published scientific theories, not accepted by later authors. His 'problem' had its origin solely in the somewhat loose language of certain text-books which described the motion of the pole of the equator as circular, the pole of the ecliptic being in the centre. This description would be correct if only the solar and lunar precessions were concerned, but planetary perturbations cause the plane of the ecliptic (and hence its pole) to shift, thus causing a variation in the radius of the circle. Drayson, without carefully studying the evidence for the shifting ecliptic, asserted that it was really fixed among the stars, and that the centre of the north pole's motion was 6° away from the ecliptic pole, thus bringing about a very large change in the obliquity, which he supposed to be near its minimum at present. It would reach 350 at its maximum, when Drayson considered an Ice- age would occur.…