[ 6 55 ] 
L ° ^ ° ther ^ Pr ° P0rtiOn ° f the fldes “ g the ** 
If from the angles at the bafe of any right-lined triangle, right lines be drawn to the 
ternate angles of rhomboids defcnbed on the other two fides, and reciprocally a P - 
p .e to them produced, a right line drawn from the vertex through the interferon of 
thefe lines will cut the bafe into two parts, having to each other the proportion 
compounded of the proportion of the fides, and of the proportion cf the* other 
two lines comprehending the rhomboids, p. 89 91. 
Theorems , a demonflration of two mentioned in art. xxv. of the Philofophical Tranf- 
aftions for the year 1775, p. 600— 603. 
Thermometer , , fome attempts to freeze its quickfilver, p, 174-177. See Qfickjiher. 
State of the thermometer in London throughout the year 1775, and P art of 1776, 
p. 320 — 350. State of it within and without at Lyndon, in Rutland, for the' year 
1 775 » P- 37 °* Of the thermometers belonging to the Royal Society, with reflec- 
tions concerning fome precautions neceflary to be ufed in making experiments with 
thofe inflruments, and in adjufting their fixed points, p. 371—385. For ap- 
plying a correction to difeover an equal heat in the quickfilver of the thermometer, 
P- 377 * State of the thermometer at Northampton during the late froft, p. 5SS 
590. An experiment with the thermometer to fee the elfedt of a high degree of 
artificial cold added to the natural, p. 590. 
Tbunberg (Dr.), his narrow efcape from drowning, p. 286, 287. 
Tides, of thofe in the South feas, p. 447. Ship lluck on a reef of coral rocks at high 
water, ibid. Next tide not high enough to float her, ibid. Night- tide rofa higher 
than the day-tide, and floated the fhip, p. 448. Times of high-water on the full 
and change days, ibid. Difference in the rife and fall of the evening and morning- 
tide, ibid. Remarks thereon, p. 448, 449. 
Tigers and wolves, frightened by fires in the night-time, p. 288. 
Time, a new method of finding it by equal altitudes, p. 92. Former method for finding 
time inconvenient, p.92,93. The inconveniencies removed by a new method, p. 
93. Manner cf finding the true zenith diflance, p. 94, 95. An example, p. 95. 
More convenient manner of inferring mean time from the liar’s meridian pafi.igc 
p. 96. An example, p. 97. The mean time of any obfervation made with a ciock 
may be inferred in a fimilar manner, p. 98. 
Tobacco mixed with hemp, Hottemots fond of it, p. 299. 
Torpedo, an account of fome attempts to imitate its efFefls by electricity, p 
Apparatus , to examine how far the phenomena of the torpedo would agree w 
19 f>. 
ith ele^* 
See Electricity 
tricity, p. 204. 210. 212 
Toumai, Rue des Jefuitcs, its latitude, p. 195- 
Traielliag, in fome places of the fouthern part of Africa, laborious and fatiguing, p. 
2 73. 277. 2/9 28l . 283. 289. 293. 503, 3O4. 3O7. 3O9. 3 I 3 - t‘ 5 ’ 2 I0> ^ 
TjgerBerg to Bay Falfo, a large fandy plain in the fouthern part of Africa, p. 26). 
Overgrown with -incite variety cf plants, ibid. Fruitful country along the utrs *-f 
TygerBerg, p. 270. v 
