INDEX TO VOLUME I. 



Page. 



Address at Metropolitan Mechanics' Institute Exhibition 306 



Address before American Association for Advancement of Educa- 

 tion 325 



^pinus, theory by, of electrical action 301 



^therial medium necessarily postulated 257, 298 



Aerial echoes, general conclusions respecting 50-4 



Aerial echo, observations on 435, 454, 471, 502 



Air, refrigeration of, by rarefaction 1 



Albany Institute, Transactions of, quoted 1, 2, 3, 8, 37 



Alcohol and water, experiments on alleged separation of 360 



Alexander, Prof. J. H., experiments by, on fog-whistles 376, 377 



Alexander, Prof. Stephen, co-operation of, in observations on mag- 

 netic intensity, at Albany, New York 60 



Alexander, Prof. Stephen, co-operation of, in observations on solar 



spots 224 



Alloys, diffusion of metals in 229 



Alternation in direction of induction currents of successive orders. 130 



American Journal of Science cited 60, 92, 449 



Ampere on electro-magnetism 305 



Annals of Philosophy, aurora borealis described in 68 



Annals of Philosophy quoted 3, 74 



Antinori, Cav., experiment by, on the influence of a spiral con- 

 ductor 108 



Apparatus used in observing magnetic intensity at Albany, New 



York 60 



Apparatus used in testing alleged spontaneous separation of alco- 

 hol and water 362 



Arago's induction by magnetic rotation 123 



Armature of magneto-electrical machine, effect of wire around 117 



Arrow, Sir Frederick, witness of abnormal phenomena of sound 415, 421 



Atomic constitution of matter postulated 255,298 



Audibility, range of, increased by elevation 458, 463, 472 



Audition, continuance of, limited to about one-fifteenth second 296 



Aurora, connected with electrical action 287 



Aurora, disturbance of earth's magnetism by 58 



Aurora, observations on 287 



Aurora, observations on the height of 260 



Babbage's induction by magnetic rotation 123 



Bache, Dr. A. D., on investigations by Ettinghausen, of Vienna, 



in armature currents in magneto-electric machine 144 



(511) 



