INDEX. 
Gibraltar Straits, obfervations on the tides there, p. 447. 
Glafs not made ufe of for magnifying objefls till the XIVth 
century, p. 124. — not ufed for windows till the time of 
Seneca at lead, p. 126 — proved from Ladtantius that 
it was ufed for windows in the third century, p. 13 1. — 
but not known in England till the time of Wilfred, in 
the feventh century, p. 132. 
Gravitation y what knowledge the ancients had of it, p. 
435 — known by Mr. Huygens that it was lefs under 
the equator, from the centrifugal force there, ibicl — ex- 
perienced by Mr. Richer, ibid fince difcovered to 
be Jeflened, from the figure of the earth there, by Sir 
Ifaac Newton, ibid. 
H. 
Halley , Dr. his tables of lives not rightly underftood, p. 
49. fee Brejlau. 
Halo , a remarkable one in May 20, 1737, P • 4 * 
Hay don , Rev. Mr. his obfervations on the tranfit of Venus, 
p. 203 . 
Heart , the late king’s fudden death owing to a rupture of 
the right ventricle, p. 2 68, 349 the ufual weight of 
it, p. 348. — lefs in bold and warm tempers than in ti- 
mid perfons and cold conftitutions, p. 353 an inftance 
of its being enlarged to a very uncommon flze, p. 344. 
Heberden , Thomas , M. D. his account of the earthquake 
at Madeira A. D. 1761. p. 1.55. 
St. Helena , ifland, obfervations made there on a clock of 
Mr. John Shelton’s, p. 434 on the tranfit of Venus 
there, p. 196. — on the tides there, 592. 
Henry , William , D. D. his account of William Carey, 
whofe mufcles began to be offified,. p. 143. 
Herculaneum , additional obfervations, by Mr. Nixon, on 
fome white glafs found there, p. 123. 
Holland , the feadykes there made with faggots of brufb- 
wood, p. 2. 
Holy-Crofs in Salop, extract from the regifter there, p. 140. 
Horizontal Sun and Moon, their apparent magnitude ac- 
counted for, p. 462. 
1 
Hudfon , 
