■ ( ) 
1c lies upon him alfo to make a publick Acknowledgment 
of his having received the Extracts of Mr. James Gregory's 
getters, which, at his own Requeft, were fent to him at 
Farts in June 1 676 by Mr .Oldenburgh toperufe: amongft 
which was Mr. James Gregorys Letter of Feb. 1 5. 1 67 1 con- 
cerning .that Series, and Mf. Nevrtns Letter of December 
10. 1672 concerning the Method of Fluxions/ 
And whereas in his Letter. of Decern. 28. 1675- he wrote 
ro Mr. Oldenburg!) , that he had communicated that Series 
.above two Years before to his Friends at Paris, and had 
written to him fometimes about it 5 and in his Letter of 
May 12. 1676 Laid to Mr. Oldenburgh that he had written to 
him about that Series fome Years before ; and in his Letter 
to Mr. Oldenhurgh dated Augi zy. 1 676, that he had commu- 
nicated that Series to his Friends above three Years before; 
that is, upon his firft coming from London to Paris : He is 
defired to tell us how it came to pafs, that when he received 
Mr. Oldenburg!) s Letter bf 2pr. 15. 1675 he did- not -know 
that Series to be his own. 
* In his Letters of July 1 and Oct oh. z6. 1674, he tells 
us of but one Series for the circumference of a Circle, and 
faith that the Method which gave him this Series, ’gave him 
alfo a Series for any Arc whofe Sine was given, tho’ the 
Proportion of the Arc to the whole Circumference be not 
known. This Method therefore, by the given Sine of 30 
Degrees, gave him a Series for the whole Circumference. 
If he had alfo a Series for the whole Circumference dedu- 
ced from the Tangent of 45 Degrees, he is defired to tell the 
World what Method he had in thofe Days, which could 
give him both thofe Series. For the Method by the Tranf- 
■mutation of Figures will not°do it. He is defired alfo to tell 
us why in .his (aid Letters he did not mention more Quadra- 
tures of*the Circle than- one. 
And if in the Year 1674 he had the Demonhration of a 
Series for findibg any Arc whofe Sine is given, he is defired 
Mm •to 
