836 



NATURE 



[February 24, 192 1 



mine absolute time can still do good work by 

 timing the exact duration of annularity ; this 

 applies especially to observers fairly near the 

 limit of annularity. Prof. Newcomb found numer- 

 ous records of this kind, made in England during 

 the total eclipse of 1715, which enabled him to 

 correct Hansen's value of the centennial motion 

 of the moon's node. Photographs taken about 

 mid-eclipse, on as large a scale as possible, would 

 be of value for determining the difference of the 

 diameters and ellipticities of sun and moon. 



Useful spectroscopic work can 

 also be done, the diminution of 

 sky-glare being of service in 

 photographing the prominences 

 or reversing layer. The British 

 .Astronomical Association, which 

 has experience of a great number 

 of eclipses, is prepared to organ- 

 ise work if a sufficient number of 

 observers send in their names. 



It is possible to reach observ- 

 ing stations by rail, either on the 

 line to Wick and Thurso, or on 

 that running westward from 

 Dingwall to Loch Alsh (for 

 Skye) ; the journej from London 

 to the eclipse zone is in the neigh- 

 bourhood of twenty-two hours, 

 and the return fare (third class) 

 in the neighbourhood of 8'i. at 

 present rates. The season is 

 probably too early for the steam- 

 boat services, otherwise these 

 would afford a ready means of 

 reaching observing stations on 

 the mainland or islands. 



Besides astronomical work, the 

 eclipse affords opportunities for 

 at least three other studies: (i) 

 Meteorological. The tempera- 

 ture is directly affected, and there are 

 frequent indirect effects on barometer, wind, 

 and cloud formation. (2) Magnetical. The 

 work of the Carnegie Institution of Washing- 

 ton, under Prof. L. Bauer, has established 

 a connection between eclipses and the elements 

 of terrestrial magnetism. Such a connec- 

 tion is in no way surprising, for the diurnal 

 variation in these elements has long been known, 

 so it is to be expected that the interposition of 

 the moon should act similarly to the interposition 



of the earth during the night hours. (3) Wireless 

 telegraphy. A notable improvement in the clear- 

 ness of signals has been ojjserved during eclipses, 

 which is again analogous to what happens during 

 the hours of darkness. Advantage might be taken 

 of this to make time comparisons for longitude 

 about the time of greatest eclipse. The eclipse 

 is large enough for this purpose throughout the 

 British Isles. The magnitude at Edinburgh is 

 0-95; Dublin, 0-94; Oxford and Cambridge, 0-89; 

 and Greenwich, 088. 



eclipse in 

 29, 1927 



Fig. I. — Track of the annular eclipse of April 8, 1921. 



There will be a total solar 

 England and Wales on June 

 (civil). The central line will run from near St. 

 David's Head to near Whitby, where the sun will 

 have risen about if hours, and totality will last 

 24 sec. At the total eclipse of January 24, 1925, 

 the track of totality will graze the Western 

 Hebrides, but with a very low sun. It will be 

 necessary to go to the neighbourhood of 

 New York for effective observations on that 

 occasion. 



Obituary. 



Prof. Emile Bourquelot. 



BY the death of Emile Bourquelot, Professor of 

 galenical pharmacy in the University of 

 Paris, science has sustained an irreparable loss. 

 Born in a small village in the Ardennes in 1852, 

 Bourquelot was apprenticed in a pharmacy in 

 Sedan while the town was still occupied by the 

 Germans. He afterwards became chief pharma- 

 cist in the H6pital Laeonec, and then successively 

 NO. 2678, VOL. 106] 



assistant professor and professor of galenical 

 pharmacy in the Ecole Superieure de Pharmacie, 

 now the faculty of pharmacy in the University of 

 Paris. Bourquelot at once devoted himself to the 

 investigation of various pharmaceutical problems, 

 but gradually restricted himself almost entirely to 

 the study of the enzymes occurring in drugs and 

 various plants, their action and the changes 

 brought about bv them in the constituents of 



