SCIENCE. 



Editorial Cojimittee : S. Xewcomb, Mathematics ; K. S. Woor.wARn, Mechanics ; E. C. Pickekino, As- 

 tronomy ; T. C. JlENDENHALL, Physics ; R. H. TiU'RSTON, Engineerin;; ; Ira Remsen, Chemistry ; 

 J. Le CoNTE, Geolofrj-; W. M. Davis, Physiography; O. C. Marsh, Paleontology; W. K. Brooks, 

 Invertebrate Zoiilogy ; C. Hart Merriam, Vertebrate Zoology ; S. H. Scudder, Entomologj- ; 

 N. L. Brittox, Botany ; Hesry F. Osborx, General Biology ; H. P. Bowditch, 

 Physiology ; J. S. Billixgs, Hygiene ; J. McKeex Cattell, Psychology ; 

 Daniel G. Brixtok, J. W. Powell, Anthropology. 



Friday, June 21, 1895. The minimum change in declination along a 



===^^^=^^^^^^^=^=^==^^^^= parallel of latitude at any particular time, and 



CONTEXTS: the minimum average seeidar change along a 



On the Distnhufion mid the Secular Variation of parallel of latitude during a given interval of time 



Terrestrial Magnetism: L. A. BauEE 673 ,, j i ji j-^- ii 



„ „ • r • . T, • ■ c. ii i occur near the equator; both quaiitities generally 



On a JMonian Liiiuvtone-Breccta m Southtrcstern i > i j j 



Jlissoiiri : Oscar Her.shey fi7f> increase on having the equator. 



Current Notes on Physiographji ( A'. ) : W". M. Exactlv the reverse is the case with re- 



Davis 67S 1 i ii • 1- ^■ 



, . , , ,r, s T, T^ XT oo<> eai'd to the mclination, viz. : — 



yotcs on Agriculture {III. ) : Byron D. HalsTED. .680 ^ ' 



Corre,s:pon(lence : — 682 ^''^ maximum change in tnclinatton along a 



Till- Illu.iliKltons in the standard Natural History: parallel of latitude at any particular time, and 



Elliott Coues : C. Hart Merriam. ^7 • 117 



„..„,. ' „^, the maximum averaqe gecidar ehanqe alonq a 



Scientijie Literature: — 684 % . ■' , . 



Vermeule\ Report on Water Sitppli/ : Geological parallel of latitude during a given interval oj 



Sioreyo/ AV,r ./en^fi/; RoLLi.v p. Salisbury. ^,-,„g (,pg„^ „g„,. (j^g equator; both quantities 



Koscoe's John Dalton and the Jiise of Modern ,,..., , . 



Chemistry: EnwAED H. Keiser. Bach's Elas- generally diminish on leaving the equator. 



ticitiitund F,.s/H/A(i7; Mansfield Merriman. rpj^^g^ j^^^^.g ^^^^ established with the aid 



The Pocht Gophers of the I nitrd States: J. .\. . , /• 



ALLEN. Collett's Norway Lemming: C. H. M. of data scaled from magnetic charts from 



Notes and Neics :— 692 1 7S0 to IS80 at points 20° distant in longi- 



Astrono,ny:Gene,al. ^^^^^ ^^^^ .^ latitudes 60°X, 40°X, 20°X, 



Societies and Academies : — ()9» „^„r. ^nr. i /.^oo mi 



Biological Society of Washington ; The Neto Jer- equator, 20°S, 40°fe and 00 b. lliey 



scy State Microscopical Society. again point to the Same conclusion reached 



'"S.^:::n^^n^;^^;n;;. ™" P'-eviously by the writer in a somewhat 



different way, namely, that the distribution 



MSS. Intended for publication and books, etc., Intended and the secular variation of terrestrial magne- 



for review should be sent to the responsible editor, Prof. J. . , t i i 1 j j ji 1 



McKeen Cattell, Garrison on Hudson, X. Y. ti.vn appear to be closely related; tliey are sub- 



Subscri|)tionsand advertisements should be sent to Science, . . ., , tj • 1 i 11 ji j 



« X. Queen St., Lancaster, Pa., or 41 East 49th St., New York. ject tO Similar laiCS. It IS hence probable tliat 



they are both to be referred primarily to the same 



ON THE DISTRIBUTION AND THE SECULAR cause. This common cause seems to be connected 



V.IRIATION OF TERRESTRIAL MAGNETISM. ;,^ ^^me tvay with the earth's rotation. 



In two papers* read before the Philo- jf ^e regard the earth as uniformly mag- 



sophical Society of Washington. May 2.Jth, uetized. having its magnetic poles coinci- 



the following main results were obtained : dent with the geographical poles, and take 



,^ . , ,, the X axis of a system of coiirdinates whose 



*'0n the Secular Variation of Terrcstniil Mag- .... , ' , , ,, ,, ,, , 



netism ' an.l ' A Prelin>inar>- Analysis of the Proble.u Origin IS in the center of the earth, parallel 



of Terrestrial Magnetism and its Variations.' tO the magnetic axis, we shall get the fol- 



