542 INDEX. 



Page. 

 Aqueous vapor, the latent heat of, very great 225 



Arago, classification by, of different forms of lightning 365, 366 



Arago, experiment by, in magnetizing iron filings and wire needles. 427, 428 



Arago, mention by, of cloud phenomena observed in the Alps 359 



Arago, observations by, on river-bottom ice 206 



Arago, remarks by, on lightning-rods 385, 386, 389, 394 



Architecture, ancient, properly a fine art 405 



Architecture, modern, subordinate to utilitarian objects 404 



Art, improvement in, dependent on the advance of science . 8 



Ascensive force of moist air increased by cloud precipitation 272, 279 



Astronomical conditions, effect of, on climate 39, 40 



Atmosphere, constitution of, and its determination 161, 162 



Atmosphere positively electrified 357 



Atmospheric circulation, motive force of 51, 52 



Atmospheric currents available for aeronautics 442, 444 



Atmospheric dust, an important subject of research 257 



Atmospheric dust, observations on 255, 256 



Atmospheric electricity due to induction from the earth 357 



Atmospheric electricity supposed to originate in the setherlal me- 

 dium 346 



Atmospheric gases the principal constituents of plants 8 



Atmospheric vapor, condensation of, warming the air 55, 56, 267 



Atmospheric vapor, elastic force of, increasing with elevation 268 



Atmospheric vapor non-diathermanous to heat of low intensity 46 



Atomic theory, exposition of 90, 91 



Atomic volumes determining series of chemical compounds 112, 113 



Attraction and repulsion, the laws of 323, 324 



Attraction of electricity by lightning-rods 392, 393 



Aurora, probably caused by earth currents of electricity 365 



Bache, Prof. A. D., experiments by, on heat absorption and radia- 

 tion of different surfaces 193 



Bache, Prof. A. D., investigations by, of acoustics applied to pub- 



■ lie halls 403 



Bache, Prof A. D., investigation of tornadoes by 292 



Bache, Prof. A. D., meteorological observations by, at Philadelphia. 178 



Bache, Prof. A. D., observations by, on inequality of rain-fall 260 



Bache, Prof. A. D., observations by, on terrestrial magnetism 349 



Bache, Prof. A. D., panoptic curve devised by, for lecture-rooms . 420 



Bache, Prof. A. D., table of diurnal variation of temperature by 44 



Balance of Nature as illustrated by the constancy of matter and 



energy 118 



Balloon voyages possible by utilization of upper and lower aerial 



currents 442, 444 



Barlow, investigations by, on electrical transmission on long wires. 433 

 Barometer, geographical plottings of, representative of storm move- 



