I N D E X/- 
571 
l.if, 43° T4 N. ; and to the Britifh Channel, Ibid. State of the thermometer in the 
foldiers barracks at Allahabad, ibid. 
Thermometrkal obfervations, an account of fome made at Allahabad, in the Eaft Indies, 
in lar. 23° 30' N. during the year 1767, and alfo during a voyage from Madrafs tu 
England in the year 1774, p. 203. See Allahabad, 
Thunder at London in the year 1774, p. 174. 
Toad, exptrlments on its power of refilling external cold, p. 4^0. 
Torpedo, experiments on, made at Leghorn, p. i. Its eft'ecT; the fame, whether the fifh be- 
in or out of water, p. i — 3. Said to have very little force in winter, and cannot live 
long out of water, p. 2. Other fidres not affefted by their company, ibid. Prelling 
gently the two foft bodies at the fide of the head, called mufeuU falcatl, produced the 
fame fenfation as if a great number of very finall eleflrical bottles were difeharged 
through the hand in quick fucceffion, ibid. Thefe fliocks ftronger at laft than in the 
beginning, p. 2. Its powers not altered by different degrees of prefTure, p.'3. When 
fufpended by a ribbon, light bodies near It not attradfed, ibid. More frequent llrocks 
caufed by the fifh bending its body, p. 4. An account of its difl'edtion, ibid. 
Torpidity of fwallows and martins, an account of the, p. 343. Appear on the banks of 
the river Dart In the beginning of November, ibid. Brought from their winter quarters 
by a fine, warm afternoon, 344. As the fun lowered, they all returned into thefifilires 
of the rocks, ibid. Not a fwallow amongfl them, Ibid. Valt flights of fwallows go 
towards the South every autumn, ibid. The feafon being uncommonly cold, the martins 
remain In the rocks. In a torpid ftate, at the end of March, p. 343. Dormice and bats 
frequently found in a date of torpidity, p. 346. Martins feen in Totnefs in Dec. and 
Jan. ibid. Three black martins or fwifts found in an old oak during the winter, p. 347. 
They recovered drength enough to fly, on being laid before a fire, ibid. The ob- 
jection brought againd the opinion that thofe birds remain torpid during the winter, 
ibid. Anfwered, p. 347 ,348. Several proofs of the torpidity of birds, p. 348 — 350. 
The opinion that fome of the fame fpecies of birds do emigrate, and others remain 
torpid during the winter, when diferedited, p. 330. vifeera of feveral torpid bats 
examined, p. 35 1. Obfervations thereon, ibid. Torpidity of animals in the winter 
accounted for, p- 433. 
Tovjns, great, in a peculiar degree fatal to children, 324 — 326. 
Triangles deferibed in circles and about them, p. 296. An equilateral triangle infcrlbed 
within a circle, larger than any other triangle that can be infcrlbed within the fame 
circle, p. 296 — 298. An equilateral triangle deferibed about a circle, lefs than any 
other triangle that can be deferibed about the fame circle, p. 298, The fquare of 
the fide of an equilateral triangle infcrlbed in a circle, equal to a reffangle under 
the diameter of the circle, and a perpendicular let fall from any angle of the tiuangle 
upon the oppofite fide, p. 299, 300. 
T’rogloe^iria, its ancient limits, p. 408. 
T’rigotiometry, 
7 
