INDEX. 
Oaks , obfervations upon them with refpeCt to lightning, 
p. 253. 
Obelijk , of St. Bride’s Church, the operations and progrefs 
of lightning there, p. 215. 
Obfervations aftronomical, how beft corrected, p. 278. 
33 b. 342. 
• made at St. Helena, 349. In the Weft Indies, 
389. See Moon , Sun, Stars. 
Oliver , Andrew, Efquire, Secretary at MafTachufets Bay, 
his letter concerning an extraordinary difeafe among the 
Indians, p. 386. 
Oxford , an eclipfe of the fun, 1 Ap. 1 764, obferved there, 
145. A remarkable meteor feen there, 326. Another, 
332. How diffimilar from other phenomena of that 
lort, 335. 
P. 
Paints , and metals, effects of handling them in fome 
cafes, p. 16. 
Parallax of the moon, how determined, p. 29. How to 
be corrected, 263.— How the apparent diftance of the 
moon from a ftar is contracted, or augmented by her 
parallax, p. 268. A rule to compute this contraction 
or augmentation, ibid. A demonftration of this rule, 
269. Remarks upon that and another rule relative to 
refraCtion, 270. How the operations purfuant to thefe 
rules are to be corrected, 271. A demonftration of 
the juftnefs of the rule for correcting thefe operations, 
2 72 , 
, - of the fun affumed by Mr. Murdoch, p. 37. A 
Supplement to Mr. Pingre’s memoir, on that lubject, 
152. His parallax from the obfervations at St. Helena, 
154. From thofe at Madrafs, 155* From ^at at the 
Ifle of France, 159. According to Mr. Short, 283. 
Penfilvania , an account of the Penfilvanian Cicada, p. 65. 
See Philadelphia. 
M m m 2 Per fans. 
