HISTORY OF PHYSICAL ASTRONOMY.

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refutation of tlie current opinion is furnished by a resolution passed at themeeting of the Council on the 2nd of June, to the effect that Sir. Newton ’sbook be printed, and “ that E. Halley shall undertake the business oflooking after it and printing it at his own charge, which he engaged todo.” The fact is, that when the Council, which took cognizance of all thepecuniary affairs of this Society, came to consider the resolution adoptedat the general meeting of May the 19th, they found that the state of theirfinances could not admit of their carrying it into effect. A work, “DeHistoria Piscium,” by Er. Willughby , had been published in 1686, “ Jussuet Sumptibus,” and the outlay incurred by this publication appears to havecompletely exhausted the funds of the Society. To such extremities,indeed, were they reduced by this act of imprudent liberalit}', that theywere compelled to pay their officers in copies of this work on fishes, inconsequence of their inability to procure purchasers for it.

Meanwhile a violent reclamation was raised by Hooke relative to thediscovery of the law of gravitation. This individual, who would be wellentitled by his genius to occupy a high place in the history of physicalscience, if he had displayed more uprightness and moderation in his rela-tions with contemporary philosophers, had no sooner heard of the manu-script which Dr. Vincent had presented to the society in Newton ’s name,than he asserted that it was he who first communicated to the author thelaw of the inverse square of the distance, as w'ell as various other dis-coveries announced in the manuscript.' We have mentioned that, as earlyas 1666, Hooke had arrived at very accurate notions on the subject ofcentripetal forces. In 1674 he published a work, entitled “ An Attempt toprove the Motion of the Earth from Observations,” in which he describesthe general nature of gravitation with remarkable clearness and accuracy.Although, however, he remarked that the attractive forces acting betweenbodies “ are more powerful as the distances from the centres are less,” it isquite clear that the idea of computing by a mathematical investigation theintensity of the force in any case at different distances from the centre,and thereby ascertaining the law of its variation, did not at all occur tohim; for, after referring to the varying intensity of the force, he thengoes on to say: “ now what these several degrees are I have not yet ex-perimentally verified.” It would appear, however, that, guided by theanalogy of other emanations from centres, he had subsequently adoptedthe inverse square of the distance as the law of the force which retainsthe planets in their orbits; and then, extending the same law to theearth, he concluded, by an inversion of the question, that the path of aprojectile was an ellipse, with the centre of the earth in the focus. Wehave mentioned already that Hooke was unable to produce a demonstra-tion of the law- of the inverse square of the distance, although he boastedrepeatedly that he had arrived by legitimate reasoning at that result.The fact is that, although a man of extraordinary acuteness in physicalmatters, he had no talents for mathematical science; and this defect con-stituted an effectual bar towards his establishing, upon a satisfactory basis,any of the great truths relating to the theory of gravitation.

But although Hooke’s powers were inadequate to the complete investi-gation of the problem of centripetal forces, there v'as much merit in theclearness with which he pointed out the mode in which a body is retainedin a curvilinear orbit by a force continually directed towards a fixed cen-tre. His views on this subject were in strict accordance with mechanical