38 INDEX. 



Thermometer, exceeded not 95° in Virginia, Vol. II. p. 143 — at 100° fa 



Philadelphia, ib. 

 , its ufe in difcovering banks, foundings, &c. at feu, Vol. III. 



p. 82, 198. 

 Thermometrica/ journals of the water and air at fea. Vol. III. p. 90, 200. 



. obfervations at Fort Wafhington, Cincinnati, in 1 790-1. 



Thomas (Rich.) and others, their account of Venus's tranfit over the fun in 



1769, Vol. I. p. 89. 

 Tin known to the Florida Indians, Vol. IV. p. 202. 

 Thomfon (Charles) his obfervations on the internal contaft in tranfit of 



Venus, Vol. I. p. 50, appendix 38. 

 Thornton (Dr. Wm.) his treatife on the elements of written language, &c. 



witli an efiay for teaching the dumb to fpeak [gained the Magellanic 



prize'] Vol. III. p. 262. 

 Thunder and lightning, a theory of, Vol. II. p. 74. 

 Time-keeptn, Rittenhoufe's improvement of, Vol. IV. p. 26. 

 Tclteca Indians, fome account of them. Vol. IV. p. 184. 

 Tornado defcribed, Vol. II. p. 342, 346. 



Torpedo, or ele>5trical eel of Surinam defcribed. Vol. II. p. 166. 

 Torporijic ff/,,or numb filh defcribed. Vol, II. p. 170 — its power compared 



with eleiflricity, 172. 

 TorriceUian vacuum, magnetic experiments in the. Vol. IV. p. 327, 

 Totuns, greateft proportion of deaths in, Vol. III. p. 41. ' 



Trade-wind, defined. Vol. 1. p. 273. 

 Traditions {Indian) Vol. III. p. 2l6, 220 — Vol. IV. p. 207, 209, 260, 



5 1 6 — not to be depended on, ib. 

 TrajeHory of the comet's path in 1770, with the elements^ of its motion. Vol. 



I. appendix, p. 37. 

 Tranjtt of Venus over the fun in 1769, as obferved at different places, Vol. 



I. p. 4, 5, 8, 13, 26, 28, 29, 32, 45, 48, 49, 50, 82, 89, 97, 105^ 



114 — appendix p. I — Vol. II. p. 246 — delineations of the tranfit, Vol. 



I. p. 36, 66 — account of obfervations on the former, 4, 2 — obferva- 

 tions on it, made at Hudfon's bay, appendix p. 4 — all the obfervations 



made therenn, colledled togetlier, appendix 12. 



in 1 761 — oblervitLiuiib on it, Vul. I. p. 6-7. 



. in 1769 — do. Vol. I. p. 82 — proje<5tion of this tranfh, 



88 — another account of the fame tranfit, appendix 50 — how ufeful 



towards fixing the longitude of places, appendix ^^. See F'enus. 



of Mercury, in 1769, Vol. I. appendix p. 50 — Vol. II. p. 249 — 



in 1782, Vol. II. p. 260 — Vol, III. p. 150. 

 Trees contribute to health, Vol. II, p. 209— the willow a great purifier of 



air, ib. 

 ■ recommended in certain fituations. Vol. IV. p. 142. 



Trepanniri", obfervations on. Vol. IV. p. 433. 

 Trichovta [Plico-Polonica] a fymptom of leprofy, Vol. IV, p. 293. 

 Trwf ^onify-iff, of America, Vol. III. p. 241. 

 Tulip-tree [liriodendron tulipiferaj ftimulant effeifls of camphor upon it, Vol. 



IV. p. 232. 

 Tumuli, in the N. W. T, &c. curious difcoveries made therein. Vol. IV. 



p. 179, 203, 20£. 



Turh'ith 



