472 



SCIENCE. 



[Vol. II., Xo. 35. 



" The differences between them [the fossils exhib- 

 ited and the Orislcany species of Eensselaeria] were 

 slight, though well marked. Professor Hall described 

 some of these differences, and Mr. Claypole acknowl- 

 edged that a certain V-shaped groove was wanting in 

 his specimens. Professor Hall thought that possibly 

 the fossils should be referred to Amphigeuia, which 

 had many similarities to Eensselaeria." 



The V-shaped groove in question is one of the 

 generic marks of Amphigenia; and its absence, there- 

 fore, was urged by me as excluding the fossils from 

 that genus, and inferentially as a strong argument in 

 favor of placing them in Eensselaeria. 



As the above-mentioned error places me (and I 

 think Professor Hall also) in false positions, and 

 involves a grave mistake in paleontology, I am In- 

 duced to ask your insertion of this correction, which 

 I have submitted to Professor Hall for his approval. 



I ought to add that the suggestion of Amphigenia 

 by Professor Hall was only the result of a momen- 

 tary impression on the first sight of the fossil, and 

 one which he immediately withdrew, on observing 

 the absence of the V-shaped groove above alluded to. 

 E. W. Claypole. 



Aurora, 



The auroral display here to-night was unusually 

 brilliant. I observed it first at 7.04 p.m. At this 

 time a low but rather brilliant arch of light spanned 

 the north-eastern horizon, the crest of the arch hav- 

 ing an altitude of about 20°. During the next three 

 minutes, the lights rapidly took on the ' streamer ' 

 form, gradually shooting upward to a little beyond 

 the zenith, and at this time stretching from east, 10° 

 south, around to west, 15° north, on the horizon. 

 During about two minutes, the waving-curtain 

 aspect was very pronounced In the north-east, after 

 which only striated patches flamed out here and 

 there, moving alternately west and east. These 

 patches all converged toward the zenith, but left 

 with one the impression of being pendulous and 

 very near. The atmosphere appeared very clear, 

 the moon full and bright, the twilight still strong; 

 and there was light enough yet to enable one to read 

 a newspaper, but with difficulty. The streamers, 

 however, lay in shai-p contrast against the blue sky, 

 even where the twilight was strongest. 



At 7.15 the lights began to die rapidly away, and 

 at 7.50 none were to be seen; but at S, and again at 

 8.13, there were distinct but small curtains to be seen 

 in the north-west. At 8.20 there began a magnifi- 

 cent display. Three large curtains formed one above 

 the other, the lowest about 20° above the horizon 

 in the north-west. They drifted gently toward the 

 zenith, swaying and folding just enough, it seemed, 

 to suit the almost imperceptible breeze which was 

 stirring. The lights could be easily seen within 7° of 

 the moon; and yet it cast its shadow on the carpet in 

 a room 13 by 14, where two kerosene-lamps were burn- 

 ing, one of them a no. 1, and the other a no. 2, burner. 

 At 9.10 scarcely a trace of the aurora could be seen. 

 A little later, a very faint diffuse light covered the 

 northern sky to an altitude of about"2o°. This soon 

 became striped, and afterwards appeared to move 

 bodily toward the zenith. At 10.20 the lower sky 

 had become a deep blue; and just above it, at an alti- 

 tude of 30°, a broad arch of bright but uniform light 

 formed across the sky; and above this, extending past 

 the zenith, were similar but much fainter bands. 

 Five minutes later, the bright band unfolded a curtain 

 which dropped in exquisite folds toward the horizon. 

 This lasted less than two minutes, the whole belt of 

 light becoming striated, but leaving a clear space next 



to the horizon; then followed about five minutes dur- 

 ing which the illuminated portion of the sky seemed 

 to be throbbing, and sending out waves of subdued 

 light, which spread southward over the blue vault, dy- 

 ing away before the zenith was reached. This move- 

 ment soon became more violent; and between 10.40 

 and 10.45 the lights had more the appearance of 

 flames bursting rapidly from the sky, and spreading 

 to the zenith, where they often turned abruptly 

 toward each other, and met. This appearance con- 

 tinued growing gradually less marked until 12.15 a.m., 

 when there was scarcely a trace of auroral display. 

 At 12.40 a faint arch of diffuse light could be seen ia 

 the north, like that already described. 



F. H. Kino. 



Kiver Falls, Wis., Sept. 16, 1883. 



THOMPSON'S PHILIPP REIS. 



Philipp Reis: inventor of the telephone. A biographi- 

 cal sketch, with documentary testimony, trans- 

 lations of the original papers of the inventor, and 

 contemporary publications. By Sylvanus P. 

 Thompson, B.A , D.Sc, professor of experi- 

 mental physics in University college, Bristol. 

 London, E. §• F. N. Span, 1883. 9 + 182 p., 

 3 pi. 16°. 



The rapid development of the literature of 

 the telephone, and the wide-spread interest in 

 matters relating to it, have rendered the most 

 important details of its history familiar to the 

 general reading public, as well as to the scien- 

 tific world. The account of the life and labors 

 of Philipp Eeis, by Prof. S. P. Thompson, 

 while repeating many of these well-known de- 

 tails, contains some interesting notices of the 

 life and personal characteristics of the invent- 

 or, and of the various steps \>y which he brought 

 his instruments to their final stage. Following 

 the brief biographical sketch, are descriptions 

 of the various forms of apparatus devised by 

 Reis, with numerous illustrations ; a statement 

 of what the author terms the inventor's claim ; 

 copies of Reis's own publications respecting 

 his invention, and of certain contemporary' ac- 

 counts of it and its operation ; with the testi- 

 monj' of persons who witnessed his esperiments. 

 An appendix discusses the variable resistance 

 of imperfect contacts, a comparison of Reis's 

 receiver with later instruments, the doctrine 

 of undulatory currents, with some additional 

 notes and references relating to Reis's inven- 

 tion. 



Had the efforts of the author been directed 

 to the presentation of these things as matters 

 of history merel3', the book might be regarded 

 as a valuable and interesting summaiy of facts 

 relating to an important invention, and would 

 demand but a brief notice here ; but a cursory 

 examination of it is sufficient to show that the 

 author has failed to maintain that judicial atti- 

 tude of mind which is indispensable to the just 



