652 



NA TURE 



[Oct. 30, 1884 



is a mean day, by M. Quet. — On the disruptive discharges 

 of Holtz's electric machine, by M. l'Abbe Maze. — On the 

 triufloride of phosphorus, by M. H. Moissan. — On the 

 results obtained from the application of potash manures to certain 

 hitherto unreclaimed lands in Brittany, by M. G. Lechartier. — 

 Fresh comparative experiments with the rabbit and guinea-pig 

 inoculated with the virus of human scrofula and tuberculosis, by 

 M. S. Arl"ing. — Note on the character and constitution of the 

 light fleecy clouds present in the upper regions of the terrestrial 

 atmosphere, by M. A. Badoureau. In these regions the author 

 assumes that the temperature falls to absolute zero, and although 

 the pressure is also reduced to zero, it seems probable that the 

 carbonic acid, nitrogen, and oxygen are here successively con- 

 densed into clouds analogous to those formed lower down by 

 vapour. To the clouds formed by these elements might be 

 attributed the phenomenal solar halos recently described by M. 

 Cornu. 



Berlin 

 Meteorological Society, October 7. — Dr. Hellmann gave 

 a short report of the proceedings of the annual meeting of the 

 German Meteorological Society, which held its sitting at Magde- 

 burg from September 18 to 22, simultaneously with that of the 

 German Natural Science Association. Communications on the 

 scientific inquiries and observations having been delivered in the 

 Meteorological Section of the Natural Science Association, it 

 was only matters connected with organisation which occupied 

 the attention of the Meteorological Society, and the most im- 

 portant of the conclusions arrived at by them formed the sub- 

 stance of Dr. Hellmann's address. — Prof. Bornstein spoke on 

 rain measurement, and, after a concise historical review of the 

 more important observations of earlier times, on the depend- 

 ence of the readings of rain-gauges on their position and exposure, 

 and on the attempts made to explain that fact, he reported 

 observations of his own which he had made for the purpose of 

 testing the influence which, according to assertions by many 

 savants, the wind exercised on the readings of rain-gauges. 

 Mr. Nipher, as was known, had in 1878 proposed, as a counter- 

 active to the influence of the wind, to surround the collecting 

 cylinder of the rain-gauges with a protective funnel. Beside a 

 Nipher rain-gauge of this construction Prof. Bornstein had set 

 another rain-gauge which was surrounded with a reversed 

 funnel, and must necessarily show the influence of the wind in 

 increased measure. By a comparison of the measurements of 

 these two gauges from January to July of this year, he ascer- 

 tained that the latter regularly collected less rain than the former. 

 The difference was greatest in the case of snow falling, less 

 in the case of a drizzling rain, still less during an ordinary 

 shower of rain, and least of all with a heavy downpour. 

 On comparing the readings of the two rain-gauges, according to 

 the strength of the winds prevailing at the times of the different 

 rainfalls, it appeared that, when the strength of the wind was o, 

 the differences were least of all ; greater differences appeared 

 when the strength of the wind was 1, still greater when its 

 strength was 2, and the greatest when it rose to 3. Winds of 

 greater violence than 3 came too seldom to allow of correct 

 determinations regarding their influence on the rain-gauges. — In 

 connection with this address Dr. Hellmann stated that at the 

 Prussian stations it was sought to abate the influence of the wind 

 by placing the rain-gauges one metre above the ground, and sur- 

 rounding them with a hedge one metre and a half in height and 

 at a distance of two metres. He then explained several models 

 of rain-gauges. — Prof. Forster reported several series of experi- 

 ments on the measurement of heat carried out by the Normal 

 Standard Commission under his direction. As a result of these 

 investigations it appeared that the possible errors of even the best 

 mercurial thermometers were very considerable. In the first 

 place, the successive expansion of the glass, if repeatedly heated 

 up to 100° C, might be very great, to the extent even of dis- 

 placing the fixed points by several degrees. The amount of 

 this change was dependent on the chemical composition of the 

 glass. According to Herr Wiebe's measurements those were the 

 worst glasses in this respect which were markedly rich in potassium 

 and sodium, especially those containing equal quantities of these 

 substances. Happily glass factories were beginning to take ac- 

 count of this circumstance in their supply of glasses for instruments 

 of precision. The expansion coefficients of the glass, and the 

 relation of the glass to the quicksilver expansion, was another 

 source of error, producing important deviations from the readings 

 of the gas thermometer. In the latter case, likewise, the chemi- 

 cal composition of the glass played a part which would require 



to be more particularly determined, and it was to be hoped that 

 the investigations now in progress would soon settle the correc- 

 tions imposed by that factor in the case. The gas thermometer 

 was itself not absolutely trustworthy, as had been shown by the 

 most recent experiments, which had demonstrated that all gases 

 employed were more or less absorbed by the glass, and the more 

 so the longer the gas remained in contact with the walls of the 

 thermometer. That this absorption prejudicially affected the 

 readings of the thermometer, if only to hundredths of a degree, 

 had been already proved. Continued experiments with nitrogen 

 and carbonic acid thermometers in vessels of glass and platinum- 

 indium would bring to light the corrections to be applied ; these 

 in conjunction with the other corrections would alone render the 

 thermometer a true scientific instrument. — Dr. Kayser has 

 photographed flashes of lightning, and obtained the ramified 

 lightning-pictures now universally known. One flash, however, 

 which he showed to the Society, was distinguished by the fact 

 that it presented four unramified, irregularly undulatory lines 

 running in exact parallels from top to bottom. These four 

 lightning-lines must, by reason of their parallelism, have arisen 

 simultaneously or immediately after one another in order that 

 their discharges should have pursued the same lightning-track. 

 The first flash was further distinguished by a series of light- 

 layers attached to one side of it. Dr. Kayser was of opinion 

 that a double discharge was here pictured, going and coming, 

 the course of which had been displaced by a strong wind (thirty 

 metres per second). The amount of the displacement could be 

 approximately calculated, and so the time between the first and 

 second discharge might be estimated to within some hundredths 

 of a second. 



CONTENTS page 



The Cholera Epidemic of 1884 629 



Dynamo-Electric Machinery 630 



Our Book Shelf:— 



Puckle's "Elementary Treatise on Conic Sections 



and Algebraic Geometry " 631 



Letters to the Editor : — 



The Cretaceous Flora of North America. — Sir J. 



Wm. Dawson ; J. S. G 631 



Palaeolithic Implements from Cambridge. — M. C. 



Hughes 632 



The Recent Lunar Eclipse. — H. Dennis Taylor. 



(lllustrattd) ■ . . . . 632 



The Red Light round the Sun — The Sun Blue or 



Green at Setting. — G. M. H 633 



The Volcanic (Dust ?) Phenomena. — T. W. Back- 

 house 633 



After-Glow. — Major Robert D. Gibney, R.A. . 634 

 The Distribution of Scientific Works Published by 

 the British Government.— Prof. V. Ball, F.R.S. 634 



Insect Pests in Ceylon. — W. L. Distant 634 



The Pentacrinoid Stage of Antedon rosaceus. — Prof. 



W. A. Herdman 634 



Curious Phenomenon. — J. T. Bottomley .... 634 

 Simson's Line. — The Writer of the Notice . . . 635 

 A Rainbow after Sunset. — James Graves . . . 635 

 Tr. pical African Mountain Flora. By Sir J. D. 



Hooker, F.R.S 635 



An Electro-Dynamometer with Extremely Light 



Suspended Coil. By Dr. W. H. Stone it 635 



Library Catalogues. By W. Odell 636 



The " Identiscope." By Francis Galton, F.R.S. . 637 

 On the Algic Flora of the Arctic Seas. By Veit 



Brecher Wittrock 638 



Notes 640 



Our Astronomical Column : — 



Variable Stars 643 



Wolf's Comet 643 



The Solar Eclipse of March 16, 18S5 643 



Geographical Notes 643 



Notes on Nitrification. By R. Wanngton .... 644 

 Researches on the Origin and Life-Histories of the 

 Least and Lowest Living Things, II. By Rev. 



W. H. Dallinger, LL.D., F.R.S 645 



Whirlwinds and Waterspouts. By. Prof. Ja-nes 



Thomson, LL.D., D.Sc ' 648 



University and Educational Intelligence 649 



Scientific Serials 650 



Societies and Academies 650 





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