July 2, 1900.] 



KNOWLEDGE. 



145 



y^ ILLUSTRATED MAG.\Z1NE <^ 



^N€E, LITER AT!]RE4ite 



Founded by RICHARD A. PROCTOR. 

 LONDON: JULY 



I'll 'it. 



PAOIi 



115 



CONTENTS. 



— ^ — 



The Total Solar Eclipse of May 28, 1900. By 1 



Waltfb XlArxDER, F.K.i.s. {lUiist rated) 

 The Corona of 1900, May 28. (Pla/e) 

 The Great Indian Earthquake of 1897. By Cuaelks 



Davison, sc.d., f.q,s. (Illuslrafed) ... ... ... 147 



American Indians. By R. Ltdkkkee. (Illustrated) ... ISO 

 Some Early Theories on Fermentation.— I. By W. 



Stanley Smiiu, th.d. . ... . . ... ... 154 



Letters : 



Is THE SlBLUlB UsiTEBSE FINITE? By ARTHUR E. 



Mitchell 155 



A Lakgb Meteob. By W. Eakp 155 



British Ornithological Notes. Conducted by Habbt F. 



WiTHBBBT, P.Z.3., M.B.O.IT 156 



Notices of Books 150 



Books KECErrED 157 



Astronomy without a Telescope.— VI. The Milky 



Way. By E. "SValtee MArxDBE. f.r.a.s. (lUuslrated) 158 



Plants and their Food. — IV. By II. H. W. Peaesos, m.a. 



(Illustrated) 1.59 



The Karkinokosm. or World of Crustacea, — 

 Fish-Bears and their Kindred. By the Rev. Thomas 

 E. K. Stbbbino, m.a., t.e.s., p.l.s., f.z.s. (Illustrated) 1G2 



Microscopy. By John H. Cookb, f.l.s., p.g.s 165 



Notes on Comets and Meteors. By W. F. Denning, 



P.B.A.8. (Illustrated) 166 



The Face of the Sky for July, By A. Fowlbe, p.e.a.s. 167 



Chess Column. By C. D. Locock, b.a. 167 



THE TOTAL SOLAR ECLIPSE OF MAY 28, 1900. 



By E. Walter Maunder, f.r.a.s. 

 In one important respect the total eclipse successfully 

 observed in January, 1898, differs from that successfully 

 observed in May, 1900. The first had its sunrise and 

 sunset limits in the inaccessible regions of Central 

 Africa and Western China respectively. Its central or 

 midday portion, however, lay across the Peninsula of 

 Hindustan, so that the observers were comparatively 

 speaking massed together, and their conditions either of 

 time or weather did not greatly differ fi'om each other. 

 The latter eclipse, on the other hand, had its high noon 

 in mid Atlantic, where there was no convenient island 

 lying in the track from which obsei-vers might view 

 the eclipse high in the sky and with the greatest total 

 phase. The observers had perforce to go either to 

 the extreme west, where the shadow track lay across 

 the southern states of North America, or to the extreme 

 east, where stations were available on the terra firma 

 of the Peninsula or the northern states of Barbary. 

 Though the sun was in no case very high, and the periods 

 of totality were short, we have in the eclipse just past 

 — since the shadow passed through clear weather fi-om 

 Mexico to Tripoli — the great advantage of being able 

 to compare results, both coronal and spectroscopic, 

 obtained before and after the interval of a few hours. 

 This comparison will be of the utmost value in deciding 



many points as to the slow or rapid change in the form 

 and direction of the coronal filaments and streamers, but 

 naturally some weeks must elapse before such com- 

 parison can be made, and at the moment I can speak 

 only of the observations secured in Algiers and the 

 neighbourhood. 



All eclipse observations tend to take on a routine 

 character, and rightly so. No fact, either in the form 

 or the spectrum of the corona, can be completely worked 

 out from the observations of a single eclipse, or even 

 three or four eclipses. Thus, though we may not now 

 expect to make any very startling discovery from tlio 

 medium-sized photographs of the inner corona, or even 

 from the very large scale ones, yet it is necessary that 

 these should bo taken regularly and in considerable 

 numbei-g at each eclipse. It is from the permanence 

 or the variation in their minor details that it will be 

 ever possible to learn the nature of the structure of the 

 corona. Of their value, even when it comes to prophesy- 

 ing the coronal form, an instance may be taken from the 

 pi-esent eclipse. From the coronal photographs of 

 1898 it was strongly suspected that there was an 

 intimate relationship between the gi-eat coronal 

 streamers and the prominences ; these lying at the base 

 of the great synclinal cui-ves, and apparently modifying 

 the fomi and nature of the corona in their immediate 

 neighbourhood. Though this could not be proved to 

 be more than a suspicion it was sufficient for us, 

 when Mr. Evershed telegraphed to us from Pont 

 Mazafrara on the morning of the 28th that there 

 was a large prominence in position angle 226°, to warn 

 Mr. Wesley and those other observers who were intend- 

 ing to draw in detail a small portion of the corona 

 in the telescope, that this region was probably the base 

 of a great ray. The event justified the prophecy, and Mr. 

 Wesley, Mr. Crommelin and Miss Leake have examined 

 with great particularity this part for comparison with 

 the photographs of the base of the great ray. 



So, too, it will be necessary to continue the observa- 

 tions of the spectrum of the " Flash " and of the corona, 

 both with the slit spectroscope and with the object- 

 glass prism, even though we may not expect them to 

 differ in any important particular from those that have 

 been taken at previous eclipses. 



Apart from these regular and routine observations, 

 several strong efforts have been made in the 1900 

 eclipse to push forward enquiries in various directions 

 into the nature and form of the sun's surroundings. 



Of these, the most important are the attempts of Sir 

 Norman Lockyer and of Mr. Evershed, by different 

 methods, to gain a more intimate and detailed know- 

 ledge of the spectrum of the " Flash." Sir Nonnan 

 Lockyer took his station on the central line in the 

 ordinary way, and relied for his success on the use of a 

 longer focal length and consequently a larger image of 

 the sun with his objective prism than has ever yet been 

 employed. lie was favoured by very clear skies, and 

 his telegrams have announced the general success of his 

 photographs. How far he has been successful in his 

 special object of finding to a more minute degree the 

 level or levels, above the sun's surface of the gases 

 which give the spectrum of the " Flash," it must of 

 course be many weeks before we can know. 



Mr. Evershed conceived a bolder plan, which proved 

 successful in all but one vital point, for which indeed 

 Mr. Evershed cannot in any way be held responsible. 

 Forsaking the central line with its many seconds of 

 totality, he took his station near the edge of the shadow, 

 wheri as he hoped his total phase would be reduced 



