Scientific Papers

IN this fourth volume Sir1 George Darwin has for the present completed the task of editing his papers, a task which he commenced four years ago on the invitation of the syndics of the Cambridge University Press. If we may judge from the fact that nine papers in the present volume have appeared since the publication of the work was started there is reason to hope that a supplementary volume will be needed before many years are past. That volume when it comes will have to contain, if it is to be consistent with former volumes, pioneer investigations of a high order in some difficult branch of applied mathematics. To one who desires to speculate along what line Sir George Darwin's future work is likely to take him the present volume is of especial interest. For in the papers classed under the head “Miscellaneous Papers in Chronological Order” will be found several early papers containing the germ of much of the later more important work. Several of these papers (notably n, 12, 13) would appear to be by-products of larger investigations which were already (we judge from the chronological list of papers) well in hand when these investigations were published. But the paper “On the perturbation of a comet in the neighbourhood of a planet,” which was followed after an interval of four years by the historic investigations on periodic orbits, does look like the first attempt along a new and fruitful line of investigation. In fact, though differing in scope and nature from the larger work, the small paper to which we have just referred might quite fairly, from a historic point of view, have been placed in the section containing the periodic orbits papers, as a preliminary piece of research. This sec tion is the most important part of the volume under review, and we must discuss it in some detail.Scientific Papers.By Sir George Howard Darwin. Vol. iv., Periodic Orbits and Miscellaneous Papers. Pp. xviii + 592. (Cambridge: University Press, 1911.) Price 15s. net.