INDEX. 201 



Transits of Venus, method of computing the sun's horizontal 

 parallax from observations of the, xx. 94 



Transmutation of metals into gold, notice of supposed instances of, 

 ix. 232 



Transplanting of vegetables, notice of experiments and observa- 

 tions on, iii. 401 



Transportation of fish from salt to fresh water, experiments and 

 observations on, xix. 235 



Trap-rocks, identity of, with certain varieties of granite, x. 29. 

 Geological resemblances between them and granite, 40. In- 

 stances in which they assume the essential characters of granite, 

 45. xi. 404 



Travellers, use of the pocket box-sextant to, xviii. 50 



Tread- wheel, application of, to canal navigation, xiv. 431 



Tredgold (Mr.), on the strength of cast-iron, xiv. 223. His 

 work commended, 224. xvii. 150. Account of his experiments 

 on the elasticity of hard and soft steel, 267. xix. 104 



Trees, importance of, in mountainous countries, ii. 57 



mode of ingrafting, viii. 154. On the latitude of, in 



Sweden, 173 



growth of, how promoted, xv. 388 



antiquity of, xix. 166 



Tren GROUSE (Mr.), contrivance of, for preserving wrecked per- 

 sons, vi. 135 



Trifolium i?icarnatuni recommended to agriculturists, xiv. 452 



Trigonometrical surveys, notice of, ix. 389 



Trinkets of gold, suggestions for cleansing, xviii. 179 



Trusses, improvement in, xiv. 433 



Tubes, experimental observations on the passage of gases through, 

 vii. 106 



— on the substitution of, for bottles in the preservation of 

 certain liquids, xix. 149 



TucKEY (Captain), notice of the voyage of, to explore the rirer 

 Zaire, v. 158 



Tumeremo (Capuchin mission of), notice of, ix. 8 



