128 RECORD OF SCIENCE FOR 1886. 



under the immediate supervision of Prof. William Harkness. The re- 

 ductions of observations made at the various stations for time, latitude 

 and longitude are finished, the determination of longitudes having re- 

 quired a thorough examination of all the great chains of telegraphic 

 longitude. A volume containing all of the observations for 1874 — all of 

 the 1874 work except the discussion of the photographs — is now in press. 

 Dr. Auwers reports, under date of January 11, 1886, that the reduc- 

 tions of the German heliometer measures are well advanced and that 

 the printing has been begun; and M. Bouquet de la Grye announces 

 for the French commission that the photographic plates, 1,019 in num- 

 ber, have bfen measured, and that the reductions are now half done, 

 and will be finished about the end of 1887. 



Theory of sun-spots. — Professor Young, in an article on "Eecent ad- 

 vances in solar astronomy," makes the following comments upon an 

 important paper by M. Belopolsky, of the Moscow Observatory, pub- 

 lished in the Astronomische ISTach rich ten. No. 2722 : 



"Some recent investigations upon the rotation of fluid masses, by 

 Jukow.^ky, of Moscow, as applied to solar conditions by his colleague Bel- 

 opolsky, seem to warrant a hope that the phenomena of surface-drift in 

 longitude, and even the periodicity of the spots, may soon find a ra- 

 tional explanation as necessary results of the slow contraction of a non- 

 homogeneous and mainly gaseous globe. The subject is difficult and 

 obscure ; but if it can be proved, as seems likely, that on mechanical 

 principles, the time of rotation of the central portions of such a whirl- 

 ing mass must be shorter than that of the exterior, then there will be 

 of necessity an interchange of matter between the inside and outside 6f 

 the sphere, a slow surfacedriit from equator toward the poles, a more 

 rapid internal current along and near the axis from the poles toward 

 the equator, a continual ' boiling up ' of internal matter on each side of 

 the equator, and, finally, just such an eastward drift near the equator as 

 is actually observed. Moreover, the form of the mass, and the intensity 

 of the drift and consequent 'boiling-up' from underneath might and 

 probably would be subject to great periodic variations. 



"This theory falls in well with the facts established by Spoerer 

 respecting the motion of the sun-spot zones, and the general though 

 slow poleward movement of sun-spots." 



Sun-spot observations at Kalocsa. — A summary (Astron. Nachr., 116 : 

 31) of sun-spot observations at Kalocsa, 1880-1885, shows the predom- 

 inance of spots in the southern hemisphere of the sun over those in the 

 northern hemisphere, particularly well marked, since the beginning of 

 1883. A similar result is shown in the Greenwich observations, and has 

 also been pointed out by Dr. Spoerer; on the other hand, from 1880 to 

 1883 the northern hemisphere had the greater number of spots. It has 

 been noticed, furthermore, that since 1880 the spots show a tendency 

 towards the equatorial zones. 



