INDEX.

TVWr-Winds, various Courses of in different Seas, in203 n. General, why they blow constantly, ii. 209.

Transparent Bodies, what, ii. 290.

Triewald , Mr. Martin, his Form of a Diving-bell, ii,I79 n. His Water-bellows, ii. 219 n.

Triplicate Ratio, what, i. 7 n.

Tropics, what, iii, 176,

Trumpet, Speaking, Nature of accounted for, ii. 242,

Tubes , Phuenomena of capillary, accounted for, i. 23 h.See Capillary. Torricelian, what, ii. 125 n. Was-ter raised in by a Weight, i. 268 n„

Tune, derived frpm aerial Pulses, ii. 250.

Twilight , what, iii. 183 n.

Twinkling of Stars, to what owing, iii, 265 n.

Tychmic System, what, iii. 97.

Typhon, what, ii. 43 n.

V.

jyrJcuum , Argument for, i. 9 n. The Deniers of deny

* Motion, i. 11 n. Absurdity of Des Cortes’s Ple-num, ibid, Torricelian, exhibited, i. 64. On theAir-pump, 156 n.

Valves, the best for Pumps, ii. 55 n.

Variation of the Needle accounted for, i. 44 n. Dr.Holies s Hypothesis, ibid. {.=? se.q.

Vapour, Quantity of, exhaled from the Sea by Heat,ii. 12 n. In the Mediterranean and Thames, ii. 13 n.Driven by the Winds to the Ridges of the Moun-tains, ii, |4 n. ' The Matter of all Meteors, i. 34 n.

Vegetation accounted for, i. 35 n.

Velocity of Motion, what, i. 91. Of a set A’Eau de-monstrated, ii. 25 n. Of the Wind, ii. 210 n.Real, of Sound investigated, ii. 236 n. Mistake ofthe Academia del cimento, ii. 238 n. Greatest Diffe-rence in, 240 n. Stupenduous, ofLight, ii. 278,279 n.

Venus, Account of, iii. 134. Appearance of in the Play-time, iij. 135 n.

Vernal Tides, why strongest, ii. 96.

Vertical Circles, fee 'Azimuths

Vibrations of a String, what, ii. 258 n.

Vilette, Mr. his Mirror, ii. 287 n.

Vision, how formed in the Eye, pi. 26. Distimst near-est Limit of, what, iii. 31 n. Distinct Limit for in

MemotS