INDEX. 467 



Page. 



Suckley, Dr. George, Explorations by 51 



Sun, the Heat and Light of, Account of Paper on 30 



Sun, on the Relative Intensity of the Heat and Light of, by L. W. Mecch 321 



L-radiated surface upon the Planets 322 



Eefraction of Light . _ 323 



Law.of the Sun's Intensity upon the Planets, in relation to their Orbits.... 324 



Resemblance of the Earth to the Planet Mars 325 



Law of Sun's Intensity at any instant during the day 326 



Climatic Features of the Globe '.. 329 



Determination of the Sun's Hourly and Diurnal Intensity 329 



Sun's Annual Intensity upon any Latitude . 335 



Annual Intensities and Annual Temperatures 337 



Average Annual Intensity on a part or the whole of the Earth's Surface... 338 



Secular Changes of the Sun's Intensity 339 



Historical Notices of Climate _ , 342 



Geological Changes . 34.4 



Local and Climatic Changes 345 



Open Sea at the North Pole 347 



Diurnal and Annual Duration of Sunlight and Twilight 350 



Half-days in the Northern Hemisphere . 355 



Increase of the Half-day at Sunrise or Sunset, by Eefraction _ 355 



Duration of Civil Twilight 355 



Duration of Astronomical Twilight 355 



Swift, Dr. , Collections by 62 



Table of Measurements for Mammals 3OO 



Tables for Calculation of the Places of the Planets, &c 27 



Tables, Meteorological and Physical 33 



Tables of the Constants of Nature and Art 289 



Terrestrial Magnetism, Apparatus for Observations, &c 37 



Testing Building Materials _ 303 



Texas, Explorations in 62 



Trinidad, Meteorology and Geology of 281 



Utah, Explorations in 62 



Ventilation, Lectures on. (See Architecture) I47 



Vollum, Dr., Collections by 62 



Wade, Major, Testing Machine 305 



Wall, G. P., and Jas. Sawkins, Geology of Trinidad 281 



Warming, Lighting, &c., of Buildings I55 147 



Warren, Lieut. G. K., Exploration of the Missouri and Yellowstone ., 60 



Wood, W. S., Exploration by 60 



Wright, Charles, Collections by 53 



