1 76 



NATURE 



\yune 22, 1882 



mais oi\ le chercha en vain. La terreu/ etait d'flUtant plus 

 grande dans la ville que le peuple, a cette epoque meme, multi- 

 pliait le. superstitions, et les sacrifices en Phonneur des divinites 

 protectrices contre les incendies. Aussi le grand mandarin de 

 Tchong-kin avait prohibe la vente et l'usa^e des allumettes 

 chimiques imp >rtees par les etrangers (yang ha) et celui du 

 petiole (yang ieon) qui avaient naguere occasioned une terrible 

 conflagration. 



Voici une note de Mr. Harding, Pingenieur charge d'elever un 

 phare a la pointe sud de Pile Formose. — Le 11 I'ecembre 1SS1, 

 vers 4I1 du matin, trois chocs distincts de tremblement de terre 

 furent ressentis." The first, of which the motion was oscillating, 

 and which was the most severe, lasted about 3 to 4 seconds ; 

 then an interval of about 10 seconds followed by the second 

 shock — an interval of 1 or 2 seconds, followed by the third 

 shock — direction from S.S.W to N.N.E. These shocks, which 

 were of great severity, were also felt in 'Pai-wan-foo and Takow 

 (environ 75 et 52 milles an nord nord-ouest du cap sud). The 

 water at South Cape rose 16 feet, causing great destruction to 

 the cargo boats moored near the beach, and was accompanied 

 by a heavy southerly swell. The water which at spring tides 

 only rises 3 feet 8 inches, had resumed its ordinary level at 

 7 a.m. 



On March 19, 18S2, at about 5 p m., a slight shock of earth- 

 quake (toujours au cap sud), with a gentle oscillating motion 

 from south to north. Duration of shock about 3 seconds." 



1'ai pense que ces curieux faits interesseraient les lecteurs de 

 Nature. 



Le Directeur de PObservatoire, 



Marc Dechev.ens, S.J. 



Observatoire de Zi-ka-wei, pres Shanghai, Chine, Avril 25 



P.S. — Une grave perturbation magnetique a ete enre^istree a 

 Zi-ka-wei le 17 Avril dernier. Kile debuta brusquement a 

 7h. 36m. du matin (temps moyen de Zi-ka-wei, longitude 

 Sh. 5m. 50s. de Gr.) par une augmentation de la composante 

 horLontale de Pintensite et une diminution de la declinaison. 

 Vers Sh. un mouvement inverse coinmenca pour se jontinuer 

 avec de larges ondulations melees de saccades brusques et nom- 

 lireuses jusqu'a 2I1. 22m. de Papres midi, moment ou la declinaison 

 atteignit son maximum, Entre le minimum, qui fut enregistre 

 quel |ues minutes apres le debut de la perturbation, et ce maxi- 

 mum de 2I1. 22m. la declinaison a vsrie de 2i' - i, valeur con- 

 siderable a Zi-ka-wei. La composante horiznntale eut son 

 minimum d'intensite (apparent a cause de la variation de tem- 

 perature) d'abord a 4h. 20m. du soir, puis encore a 7b.. 20m. du 

 soir. Ou pent se rendre compte de Penorme baisse enregi-tree 

 en cette occasion, en sachant que le 19, par exemple, ou la 

 variation dela composante fut normale, la courbe photographiee 

 a une amplitude totale de 15 millim, tandis que le 17 pendant 

 la perturbation la variation totale s'eleva a 76 inillim. entre 

 7I1. 36m. du matin et 4I1. 20m. du soir. Les grandes ondula- 

 tions se des-inerent pendant le minimum d'intensite entre 2I1. du 

 soir et loll, du soir. Vers nh. 30m. du soir la composante se 

 releva tres-brusquement, oscilla encore 3 ou 4 fois ce vers 3I1. 

 du matin 18 la perturbation etait finie. A cette augmentation 

 brusque d'intensite corresponds une diminution non moins 

 rapide de la declinaison, suivie anssitut apres d'une forte 

 ition qui mit aussi fin a la perturbation de cette 

 b ussole. 



Pendant tout ce temps Paimant de la composante verticale 

 oscilla constamment mais dans de tres-petites limites ; il n'y eut 

 que deux ondulations qui se dessinerent assez nettement, i'une 

 entre S.[ et 84 du soir Pautre a 11.30. 



Le 20 Avril, nouvelle perturbation aussi interessante com- 

 mencant avec une soudainete et une violence extraordinaire a 

 Ilh. 40m. du matin par une enormediminulionde la composante 

 honzontale, suivie de sauts ou d'ondulations amples et assez 

 rapides. Inutile de dire que la declinaison a vane propor- 

 tionellement et en sens inverse. Le maximum de declinaison 

 fut enregistre a 3h. 43m. de Papres-midi ; entre le minimum 

 normal de 9I1. et ce maximum de Papres-midi la variation a ete 

 de ij'2 seulement. La perturbation prit fin a 2I1. 20m. du 

 matin le 21, quoique la declinaison continual a ctre irreguliere 

 dans la journee. 



A cette double perturbation magnetique ont correspondu des 

 troubles profonds dans toutes leslignes teiegraphiques, marines ou 

 terrestes, de Pextreme Orient, de Singapore et Manille jusqu'a 

 Tientsin. Les moments ou les courants perturbateurs furent 

 observes furent surtout, le 17, entre loh. et midi (Nagasaki- 

 Shanghai Shanghai- Hongkong), a midi 50m. (Hongkong-Amoy. 



Shanghai), a ce moment la correspondance entre Hongkong, 

 Manille, et Singapore entierement interrompue ; entre 2h. 5m. 

 et 2h. 20m. Shanghai Amoy). Le 20, a midi (Shanghai- 

 Nagasaki). 



Tout cela indique pour PEurope de belles aurore boreales. Ici 

 rien. 



Non-Electric Incandescent Lamps 



It is I believe well known that a method of obtaining light 

 by means of incandescent platinum was patented by A. Cruck 

 shanks in 1839. The following extracts from his specification 

 (No. 814 1 ) will, I think, show that there is no essential difference 

 between the lamp devised by Prof. Regnard (Nature, vol. xxvi. 

 p. 108) and the invention of the patentee, which is described as 

 follows:— 



" In order to increase the light obiained from substances that 

 are rich in carbon and to obtain light from gases and vapours 

 that do not contain the proportions of carbon necessary to pro- 

 duce a bright flame. I construct a cage 1 f fine platina wire gauze 

 or network of the form of the flame and just so much smaller 

 than the flame, that it may be entirely immersed in the outer 

 portion of it, where it will soon become intensely ignited." 



Further on it is stated that the platinum (covered with lime) 

 may be heated by jets of the "vapour of inflammable liquids 

 mixed with atmospheric air," and the patentee says that "the 

 most advantageous method in practice" of obtaining the mixture 

 " is to pass a current of air through such liquid." 



The use of incandescent platinum as a source of light was 

 again patented in 1S49 by Gillard, and put in practice it Nar- 

 bonne and some other small towns in France, but after a fair 

 trial the experiment was abandoned (see King's "Coal Gas," 

 vol. i. p. 53). F. M. Sexton 



6r, liarrington Road, S.W., June 12 



Conservation of Solar Energy 

 The views of Dr. C. William Siemens suggest a consideration 



of the influence of solar rotation upon the aethereal atmosphere, 



at various distances from sun's centre. 



Laplace's limit of equal rotary and planetary velocity is at 



3635 r a , r o , being sun's semidiameter. The centrifugal force of 



rotaiion at that limit would be I32i'3 times as great as at sun's 



surface, while the centripetal force of gravitation is only 



as great. The lately-published photographs of the solar eclipse 

 indicate an atmospheric oblateness which may be due to the 

 equilibrating ten lencies of the two opposing forces. 



If the ethereal disturbances from this source are not sufficient 

 to account for luminous and thermal vibrations, we may look 

 next to the velocity which the subsiding particles would acquire 

 in falling from the equatorial limit to the solar poles. If there 

 were no resistance, this velocity uould be 



f 35 35 x 2 gr ) =3768 miles per second. 



Any diminution of this velocity by resistance would be converted 

 into heat. 



if we apply Coulomb's formula of torsioml elasticity, 



/ = 



■rd-tl ' 



to solar rotation, IV may represent sun's mass, a 



the coefficient of the radius of torsion,/the coefficient of torsion, 

 ;• gravitating acceleration at sun's equatorial surface, t time of 

 oscillation when the force of torsion is removed, or time of a 

 solar half-rotation. Then 



/= ^=Z.^;..,r«V.=^W/. 

 J 2 2 gP 



But g', or the projectile velocity that is represented by sun's 

 rotary oscillation, is the velocity of light ; gf is the modulus of 

 light at sun's equatorial surface ; i7°r t is the theoretical length of 

 a pendulum, at sun's surface, which would oscillate once in each 

 half rotation ; ar s is the length of an equatorial radius rotating 

 with sun, and having the superficial orbital velocity, * gr, at its 

 emote extremity. Pliny Earle Chase 



May 27 



The Function of the Ears in the Perception of Direction 



Unfortunately, through the bungling of my late agents, I 

 am unable to refer to Nature, vol. xxiv. p. 499, as quoted by 



