VOL. XXV.J PHILOSOPHICAL TRANSACTIONS. 32$ 



Gregory, against the calumnies of the Abbot Galloys, who also impeached before 

 the learned world the great Dr. Barrow,* as if he had stolen from Roberval 

 his propositions concerning the transformation of curves. And now, since M. 

 Galloys has thought fit to revive the same controversy again,f I may be again 

 allowed to vindicate my uncle's reputation. 



M. Roberval lived seven years after Mr. J. Gregory's book was published. 

 Now is it to be supposed that he, who was catching at every little advantage, 

 who was arrogating every thing to himself, and who would leave no one in 

 quiet possession of his own, can it be supposed that he would allow himself to ' 

 be rifled of his propositions while he was living, and having the use of his eyes ? 

 but M. Galloys says, he did not see it, he read no new books at that time, he 

 patiently suffered himself to be robbed of his discoveries, he gave up his fame 

 together with his mathematics. It is surprising with what face he can utter such 

 fictions as these, which can so easily be refuted. So little truth is there in hi 

 assertion, that from the year 1 668 Roberval lived in retirement, remote from 

 the conversation of learned men, and had renounced his mathematical studies ; 

 that, on the contrary, from the year 1670 he was a professor of mathematics 

 in the Academy of Paris, and communicated to the Royal Academy of Sciences 

 his invention of a new balance, as testified by their acts, published for that 

 year.:): Roberval was therefore present at the meetings of the academicians, 

 and if he then read nothing himself, can it be supposed that he heard nothing in 

 conversation about Gregory's inventions, which were then so celebrated in 

 France ? Did he hear nothing about them from Huygens, who at that time spoke 

 very eagerly against Gregory among the academicians?^ But if there was no 

 familiarity between him and Huygens, as Galloys affirms, perhaps because he ^ 

 was displeased that Huygens had discovered the most useful property of the 

 cycloid, could he yet hear nothing for the whole space of seven years from all 

 the rest of the academicians ? or if he did hear, did he make no complaint to 

 his brethren and friends ? who can believe he had such a contempt for fame, 

 that has but once heard of his squabbles with the Italians, with his own people, 

 and with every body ? If of a sudden he was become so indolent, and so indif- 

 ferent to reputation, that he could quietly bear to see all his discoveries ascribed 

 to others, and to suffer what he had happily invented rather to lie dormant in 

 his study, than to bring them to light ; how then could Gregory steal these 

 things from him ? 



But let us see by what force of argument it is that Galloys proceeds to fix 



* Hist, of the Royal Academy, l603. + Ibid. 1703. 1 Journal des Scavans, 167O. 



§ Ibid. 1668. 



YOL. V, U U 



