448 



Cyanotype, 197. 



Cylinder or tube, vibration of, 147. 



, electro-dynamic, 319. Note 



219. 



Daguerreotype, 195 



Dalton, Dr., his laws of definite pro- 

 portion, 102. His experiments on 

 evaporation, 228. 



Damoiseau, M., his computation of 

 the perturbations of Biela's comet, 

 347. 



Daubuisson, M., on the temperature 

 of mines, 242. 



Davy, Sir Humphry, his opinion of 

 electric light, 279. His decompo- 

 sition of the earths and alkalies, 

 296. His experiments" on the trans- 

 mission of the electric fluid, 335. 



Davy, Dr., his experiments on ani- 

 mal electricity, 335. 



Day, the length of, invariable, 72. 



, astronomical and sidereal, 81. 



Note 145. 



Declination, 83, 89. Note 154. 



, cosine of, 90. Note 154. 



Definite proportion, 102. 



of electricity, 103. 



Degrees, minutes, and seconds of 

 arcs, 9. Note 50. 



of the meridian, mensuration 



of, 46. 



Delambre, M., his computations 

 show that the length of the year 

 has not been increased by the 

 action of comets, 338. 



De la Rive, M., determines the tem- 

 perature of an Artesian well, 244. 



De Laroche, M., his experiments on 

 the transmission of caloric, 210. 



Density of bodies, 56. 



of the sun and planets, 56. 



of the ocean, 45, 48. 



of the earth, 73. 



Depth of the ocean, 50, 72, 86. 



Deviation of light. Note 191. 



Dew, the formation of, 221. 



Diameter, 2. Note 1. 



of the sun and earth, 55. 



of the moon, Jupiter, and Pal- 

 las, 26, 51, 55. 



, apparent, of the sun and plan- 

 ets, 38, 55. Note 110. 



Dicotyledonous plants, 267. 



Diffraction of light, 168, 175. Notes 

 193, 196, 197. 



Dip, magnetic, 301. 



Disc, the apparent surface of a heav- 



enly body, 29. 

 Dispersion of light, 158. Note 90. 



- on the undulatory theory, 191. 

 Displacement of Jupiter's orbit and 



equator, 28. Note 90. 

 Distance of the sun and planets, 53. 

 Note 132. 



- of the moon, 4, 33. Note 17. 



- , perihelion, 10. Note 57. 



- of the fixed stars, 54, 362. 



- may ie found from the multi- 

 ple systems, 370. 



- , lunar, 37. 



- , inverse square of the, 5. Note 

 23. 



- , zenith, 83. Note 149. 

 Disturbing force, 14. Note 63. 



- of the sun, 34, 78. Note 101. 



- of the planets on the moon, 35. 



- of the moon on the earth, 74. 



- of the moon on herself, 35. 

 Division of time, 78. 



- , decimal, 79. 



Doabereiner, M., his experiments on 

 the combustion of platina, 104. 



Dollond, Mr., his achromatic tele- 

 scope, 159. 



Double refraction, 175. Note 200. 



- stars, 365. 



Dunlop, Mr., his catalogue of double 



stars, 368. 

 Duperrey, Captain, his determina 



tion of the magnetic equator, 302. 

 Dusejour, M., proves that a comet 



cannot remain long near the earth, 



338. 

 Dynamics, the science of force and 



motion, 308. 



Earth, form of the, 5, 43. 



- , from arcs, 45. 



- , from pendulum, 47. 



- , from lunar theory, 39. 



- , from precession and nutation, 

 50. 



- , from the mean of all, 49. 



- , mean diameter, circumference, 

 polar and equatorial radius of the, 



- , density of the, 56, 73. 



- , internal structure of the, 73. 



- , central heat, and temperature 

 of the, 67 et seq., 241 et seq. 



- , magnetism of the, 300. 



- , magnetic by induction, 330. 



- , rotation of the. See Rotation, 



