170 



NOTES AND QUEKIES. 



[2»4 S. VI. 139.. Aug. 28. '58. 



To what your correspondent has given should 

 he added that the very apple-tree from which 

 Newton's apf.le fell — I mean Mrs. Conduitt's 

 apple, not the moon — lins been settled. The fol- 

 lowing is Sir David Brewster's note upon the sub- 

 ject (vol. i. p. 27.) : — 



" Neither Pemberton nor Whiston, who received from 

 Newton himself the History of his first Ideas of Gravity, 

 records the story of the falling apple. It was mentioned, 

 however, to Voltaire by Catherine Barton, Newton's 

 niece, and to Mr. Green "by Martin Folkes, the President 

 of the Royal Society. We saw the apple-tree in 1814, and 

 brought awaj' a portion of one of its roots. The tree was 

 so much decayed that it was taken down in 1820, and the 

 wood of it carefully preserved by Mr. Turnor of Stoke 

 Eocheford. See Voltaire's Pliilosophie de Newton, 3me 

 part. Chap, iii.. Green's Philosophy of Expansive and 

 Contractive Forces, p. 972., and Eigaud's Hist. Essay, 



,, 9 » 

 1 • ■" 



" Sir, he made a chimney in my father's house, 

 and the bricks are alive at this day to testify it, 

 therefore deny it not." I shall now proceed to 

 some grave criticism upon the whole story. 



First, was it an apple ? This is very important. 

 Voltaire only says, les fruits d'un arhre. Folkes 

 certainly says, pomum, but this word is only some 

 round fruit. Is it not Virgil who talks of the 

 poma of a mulberry-tree ? If Hegel could have 

 thought objectively for a moment or two, he 

 would have seized these points. Next, though 

 the story is mentioned in the draft of the account 

 sent to Fontenelle which is found in the Conduitt 

 papers, it does not occur in the eloge which was 

 the consequence. Now, looking at the fact that 

 Fontenelle was a writer who loved anecdote, and 

 was very unlikely to omit so possible and pleasant 

 a story as that of the apple, there is strong pre- 

 sumption that either Mrs. Conduitt or her husband 

 struck it out, and did not transmit it to Fontenelle. 

 There is then nothing certain except that Newton's 

 niece talked about some fall of fruit, and that we 

 have recollections of her conversation by Voltaire 

 and Folkes. If we remember how conversations 

 grow by repetition, we may think it possible that 

 Newton, in casual talk, mentioned the fall of some 

 fruit as having once struck his mind when he was 

 pondering on the subject of the moon's motion, 

 and that Mrs. Conduitt made too much of it. 

 Hence Green's pomum, and its common rendering 

 of apple, followed by the actual discovery that 

 there was an apple-tree at Woolsthorpe, and, it 

 should seem, only one. 



The story of the apple is pleasant enough, and 

 would need no serious discussion, if it were not 

 connected with a remarkable misapprehension. 

 As told, the myth is made to convey the idea 

 that the fall of an apple put into Newton's mind 

 what had never entered into the mind of any one 

 before him, namely, the same kind of attraction 

 between celestial bodies as exists between an 

 apple and the earth, In this way the real glory 



of such men as Newton is lowered. It should be 

 known that the idea had been for many years 

 floating before the minds of physical inquirers, 

 in order that a proper estimate may be formed 

 of the way in which Newton's power cleared 

 away the confusions, and vanquished the diffi- 

 culties, which had prevented very able men from 

 proceeding beyond conjecture. 



In 1609 Kepler published his famous work on 

 the planet Mars, in which he establishes his cele- 

 brated laws; in 1618 he published h\s Epitome 

 Astronomies Copernicana;. Newton began to think 

 of gravitation in 1666. In both works, but es- 

 pecially * in the second, Kepler raises the idea of 

 the planets being moved by a force from the sun. 

 He lays especial stress on the fact that the nearer 

 a planet to the sun the more rapidly does it move. 

 And he implies and inclines to the hypothesis that 

 this force must be inversely as the distance from 

 the sun. In 1645, when Newton was three years 

 old, Bouillaud (see Penny Cyclopcedia) published 

 his Astronomia Philolaica, in which he combats 

 Kepler, and makes the very remarkable anticipa- 

 tion that the force, if any, could not be inversely 

 as the distance, but as the srptare of the distance. 

 In 1673, before Newton had published anything, 

 Huyghens published his Horologium Oscillator iron, 

 at the end of which he gave the complete results 

 of circular motion, without demonstration. We 

 here find, so far as the circle is concerned, the 

 very propositions on centrifugal and centripetal 

 balance which Newton gave in the Principia. 

 We may presume that Newton, a learned mathe- 

 matician as well as an inventive one, knew both 

 Kepler and Bouillaud in 1666. On Newton and 

 Huyghens I shall probably propose a query, when 

 I have further considered a point to which this 

 article has drawn my attention. 



What then did Newton do? He compared the 

 fall of the moon with the fall of a stone, and showed 

 that the effects are as the inverse squares of the 

 distances. He deduced Kepler's laws as conse- 

 quences of this hypothesis, and connected elliptic 

 motion with the law of the inverse square of the 

 distance. He abolished the mysterious centre to 

 and from which motions were supposed to take 

 place, and introduced universal gravitation (the 

 adjective, not the substantive, is Newton's dis- 

 covery) : showing that if every particle attract 

 every other particle inversely as the square of 

 the distance, a whole sphere will attract as if its 

 mass were collected at its centre. This last, one 

 of the most important points of Newton's con- 

 nexion of theory and fact, has nothing which 

 strikes : for people in general would imagine that 

 the result must be true in all cases. But in truth 

 it is true only for the inverse square, and for the 

 direct distance, a law which is out of the question. 



* I will not answer for the first edition • the one before 

 me is of 1635. 



