March 1, 1900.] 



KN O WLEDGE 



49 



llLtiSTRATED MAG.\Z1NE 



Founded by RICHARD A. PROCTOR. 



LONDON: MARCH 1, 1900. 



CONTENTS. 



The Coming Eclipse of the Sun. Bt E. Waltee 

 MArypER, F.ii-A.s. 



Maps showing the Path ot the Moon s Shadow. (^Plate) 



Electric Auto- Portraits. l!y Alex. 1'uubbdbn. (Illus- 

 frate<l) 



Polarity in Magic Squares.— II. By E. D. Littlb. (Illus. 

 trated) 



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

 (Illustrated) 



Notices of Books 



Books Rkceitbd 



British Ornithological Notes. Conducted by Haebt F. 



VTlTHBBBT, P.Z.S., M.B.O.U. ... 



Astronomy without a Telescope.— II. The Zodiacal 

 Light. Hy E. Waltee ilArxDBB f.R.a.s. (Illustrated) 



Letters : 



The Eaewig as a Benefactoe. By Waltee Wesche... 

 Some CuBiors Lu>ab Phenomeka. By Walter 



Williams, m.b 



Thb CoxsTiirESTs OF THE SuN. By Col. E. E. Maekwick 

 Obseetations of Vabiable Stabs. By David Fljxeet 

 Is the Stellas Unitebse Finite ? By C. E. Inqlis, b.a. 

 Seal IX Suffolk. By Jos. F. Green 



Some Wild Indian Tribes. By K. Lydekkee 



Photographs of Toda Man and Girl, and a Vedda Man 

 and Woman. (I'lat,) 



Microscopy. By John H. Cooke, f.l.s., p.g.s 



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

 F.B.A.8 ' 



The Face of the Sky for March. By A. Fowleb, j.e.a.s. 



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



PAOE 



:>i 



51! 



55 



58 

 60 



60 



61 



64 



64 

 64 

 65 

 65 

 67 

 67 



C9 



71 

 71 



THE COMING ECLIPSE OF THE SUN. 



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



The great success which attended the exjjcditions that 

 went out to watch the Indian Eclipse of 1898, will, il 

 is to be hoped, have quickened the interest in eclipse 

 work, and will lead to that of the coming May being 

 observed yet moi-e thoroughly. Political events have 

 drawn attention into other directions, but it is so 

 seldom that so good an opportunity is afforded to tha 

 inhabitants of these Islands to observe an eclipse with 

 so little or so easy travelling, that it would be a great 

 misfortune if the occasion were not utilized to thj 

 utmost. 



The path of the eclipse is as follows: — It begins on 

 the Pacific Coast of Mexico, where the eclipse begins 

 at sunrise ; the shadow track crosses the north-west 

 angle of the Gulf of Mexico, and strikes the United 

 States in Louisiana. Travelling in a north-easterlv 

 direction it passes over New Orleans, and traverse* 



in succession the states of Mississippi, Alabama, 

 Georgia, South C;u-olina, North Carolina, and reaches 

 the Atlantic at Cape Henry in Virginia; Columbus 

 in Georgia, Raleigh in North Carolina, and Norfolk 

 in Virginia being the chief towns near the central line. 

 Then the eclipse crosses the Atlantic, and the longest 

 duration of totality takes place when it is a little losK 

 than half-way across, conic 350 miles cast of New- 

 foundland. 



Tho shadow traik iie.^t louclies land in Portugal, at 

 a seaside resort named Ovar, some fifty miles south of 

 Opoi-to. The eclipse is total for a few seconds at 

 Oporto itself as it lies just within the .shadow track. 

 Crossing the Peninsula to tho Mediterranean coast, wi 

 find a few miles south of the port of Alicante, a quaint 

 semi-Moorish littlo town named Elche, and a straight^ 

 line joining Elcho with Ovar very nearly represents 

 tho path of the central shadow. 



The ti'aek then crosses the sea again, this time acrosi 

 the Mediterranean, and tho central line meets tho 

 African coast almost precisely at Cape Matifou, the 

 eastern horn of the bay on the western side of which 

 stands the city of Algiers. The line then passes east- 

 waixl, nearly bisecting the province of Tunis, and 

 entering the Gulf of Cabe,-;, skirts the coast of Tripoli, 

 and ends at sundown as i(- reaches the eastern shore of 

 the Gulf of Sidra. 



It will be seen from the foregoing that there are two 

 great regions where the eclipse may be observed, the 

 one on the west of the Atlantic, where the eclipse takes 

 place before local noon, the other on the east of tho 

 Atlantic, where it takes place after local noon 



It is, of course, always a matter of great importanc» 

 that tho sun should not be near the horizon at tho timo 

 of totality; the chance of cloud being so much greater 

 in the case of a low sun, and atmospheric absorption 

 necessarily intei-fering to a greater extent. We may, 

 therefore, leave out of consideration that part of the 

 shadow line which lies in Mexico, and commence witb 

 it as it enters tho United States, near New Orleans. 

 Here the sun will bo 30'^ high at the time of mid- 

 eclipse, which will take place at about 7.30 a.m., 'oca'. 

 time, and totality will last for 78 seconds. At Cape 

 Henry, on Chesapeake Bay, the sun's altitude will be* 

 47°, the local time 8.49 a.m., and the duration of 

 totality 106 seconds. On the line joining these two 

 stations, the altitudes, local times and durations of 

 totality may be inferred pretty closely from their dis- 

 tances from the two extreme stations. Thus, at Union 

 Point in Georgia, nearly midway between them, we 

 find the sun's altitude 39^, the local time 8h. Sm. a.m. 

 and the duration 92 seconds. 



Cape Heni-y, Virginia, gives us the longest duration 

 for any land station for this eclipse, but when we raiso 

 the question of weather probabilities we find that 

 neither the Atlantic nor the Gulf Coasts of the Unito,< 

 States are very promising. The weather Bureau o! 

 the United States Department of Agriculture has care- 

 fully collected the cloud statistics of a largo number of 

 stations, with the result of showing that the interior 

 of Soutli Carolina, Georgia, and Alabama, where the 

 shadow track crosses the southern end of the Appala^ 

 chian Mountains, offers much the best prospects, and 

 the chances of a clear sky seem to diminish in pro- 

 portion as the coast is approached in either direction. 

 In all tho three states named tho weather conditions 

 seem as favourable as can possibly be expected. 



Crossing to Europe, we find the sun 42° high at 

 Ovar, the local timo 3.28 p.m., and the duration of 



