CONTENTS. 
LIV. Ext rail of a Letter from Profejfor Bofe, of 
Wittemberg, to the Right Hon. George Earl of 
Macclesfield, Pr. R. S. with Observations there- 
upon , by Mr. Wm. Watfon, F. R. S. p. 3^8. 
LV. Jn Account of a Memoir , read at the Royal 
Academy of Sciences at Paris, by M. de Barros, 
a Portuguefe Gentleman , concerning certain ‘Phe- 
nomena obferved by him at Paris, in the lafl 
Tranfit of Mercury over the Sun ; by J. Short, 
A. M. F. R. S. p. 361 . 
LVI. An Explication of an obfeure Pa [[age in 
Albert Girard’j Commentary on Simon Stevin’j 
Works 5 by Mr. Simpfon, Profejfor of Mathema- 
tics at the Univerjity of Glalgow : Communi- 
cated by the Right Hon. Philip Earl Stanhope. 
p. 36 8. 
LVII. Obfervations upon the Ele&ricity of the Air, 
made at the Chateau dc Maintenon, during the 
Months of June, July, and O&ober, 17^3 ; being 
Part of a Letter from the Abbe Mazcas, F. R. 6. 
to the Reverend Stephen Hales, T. T). F. R. S. 
Tran flat ed from the French by James Parfons, 
AI T). F.R.S. p. 777. 
ERR AT A: 
Page 201, for Art. XXXII. read XXXI. P. 34, Note (1) for 
Tab. I. read Tab. II. In Sheet (Y) for 173, read 169. For 176, 
read 172. For 177, read l 73. And for 180, read 176. 
Page 333, Note (2) for Tab. 111 . read Tab. II. 
I. An 
