May 1, 1895.] 



KNOWLEDGE. 



107 



Dolgan, and five Yakuts. The chief aim of the expedition, 

 the bay of the Anabar, was reached on September 2nd, at 

 Cape Buskhaya. Good weather set in, and for a full 

 month they had a succession of bright, warm days. Lieut. 

 Shileiko was thus enabled to make a fundamental survey 

 of Anabar Bay, as well as of the Anabar Eiver, as far as 

 the mouth of the Uja, at the limits of tree-vegetation — 

 that is, for a distance of two hundi-ed and seventy miles. 

 At the same time the high crags of the bay and river 

 (attaining in places heights of three hundred feet) afiforded 

 Baron Toll the possibility of obtaining a full picture of the 

 geological structure of the region, and he gathered a rich 

 collection of the fauna of the lower chalk deposits, of which 

 the plateau between the Lena and the Anabar, and 

 probably also the country further north, up to the 

 Khatanga, is composed. In the five different horizons of 

 the lower chalk, which he thus investigated, he found all 

 the Mesozoic fossils, and especially the ammonites of 

 doubtful age, which had previously been found in North 

 Siberia, either isolated or in boulders, and thus he was 

 enabled to ascertain their proper place in the succession of 

 fossils of that age. 



After having completed their work on the Anabar, the 

 explorers, instead of returning by the already known route 

 to Bulun, took a new one, and connected their surveys with 

 Dudinskoye on the Yenisei. Baron Toll, having to return 

 to Bulim for his collections, parted company with Lieut. 

 Shileiko, who lost no time in moving westwards. 



Meeting again at Khatangskoye, the two explorers 

 started for their home journey, which they accomplished 

 with remarkable rapidity. It took them but thirty days 

 to reach Yeniseisk, and twenty-three days later they were 

 at St. Petersburg. 



The results of the expedition are encouraging. Over 

 three thousand miles were surveyed, being based upon 

 thirty-eight points, astronomically determined ; nine 

 months of meteorological observations in the tundras were 

 noted ; hypsometrical measurements along the whole of 

 the route were made, while one hundred and fifty 

 photographs and very rich collections of botanical, 

 zoological and ethnographical specimens were obtained. 



It should be added that Baron Toll was also to keep a 

 good look-out for the Fmm and the Nansen expedition, 

 which, as originally settled, was to call, and even winter 

 at the New Siberian Islands, but as no traces whatever 

 were found of that expedition, it is concluded that Nansen 

 found the sea so open to the north-east that he did not 

 call, in order to avoid delay, but steered direct into the 

 Polar pack, which he beheves is to carry him across the 

 Pole and south to Spitzbergen. 



The two photographs accompanying the present paper 

 were taken by Baron von Toll, and placed at the disposal 

 of the writer. 



NOTES ON A SOLAR PHOTOGRAPH. 



By E. Walter Maunder, Hon. Sec, B.A.S. ; President 

 British Astronomical Association : Superintendent of the 

 Phi/sical Department, Royal Observatory, Greenwich. 



THE readers of Knowledge are indebted to M. 

 Janssen, Director of the Meudou Observatory, for 

 the fine solar photograph reproduced in the 

 present issue. The original negative was taken 

 on April 1st, 1894, and was then enlarged, for the 

 special district shown, to a scale of one metre to the solar 

 diameter. This has been slightly enlarged further in the 

 process of reproduction. The plate being too large as it 

 stood for a page of Kndwledge, it has been divided into 



two, but the relation of the two parts has not been other- 

 wise disturbed. The upper and lower edges of the two are 

 in the same straight line with each other, and the following 

 edge of the one corresponds to the preceding edge of the 

 other. 



The first point of interest in the photograph, of course, 

 attaches to the three considerable groups of spots, which, 

 together, form indeed a very fairly typical area of disturb- 

 ance ; not one of the greatest outbreaks, but one of at 

 least the second order of magnitude. On April 1st, the 

 day in question, the total area of the three groups was 

 2300 millions of square miles, just one five-hundreth part 

 of the entire visible hemisphere of the sun ; the three 

 separate groups registering GOO, 1580, and 180 millions of 

 square miles respectively. A comparison with photo- 

 graphs taken on the preceding and following days shows 

 that the three groups were still on the increase on April 1st, 

 though they were not far from their greatest development. 

 This was reached on AprO 4th, after which a rapid decline 

 set in. 



As will be seen from the Uttle sketch map given in 

 Fig. 1, which shows the relation of the three groups to 



Fig. 1. 



-Tlio S\in on April 1st, 1894; showing poeitious of 

 tile chief Spot-groups. 



other spots on the sun and to the general disc, the western 

 group was on the central meridian at the time when the 

 photograph was taken. The groups are, therefore, shown 

 at their best and fullest presentment to us, as well as when 

 they had nearly attained their largest size. 



The history of the three groups is of a very ordinary 

 kind. Distinguishing them as "western," "northern," 

 and "eastern" respectively, the western group was first 

 seen as a number of somewhat small spots, closely packed 

 together in an irregular cluster, and surrounded by a 

 considerable mass of faculas. By the next day the group 

 had apparently lengthened out a little, an effect, however, 

 due only to the diminution in the foreshortening. But 

 by March 29th a real lengthening, as well as an apparent 

 one, was evident, due to the motion forward of the leading 

 spot, which was at the same time rapidly increasing in 

 size. Thus from an area of 14 millions of square miles 

 on March 28th, it had increased to 640 millions on 

 April 4th, a growth of 626 milHons of square miles in a 

 single week. The forward motion in longitude had not 

 lasted so long, coming to an end on April 2nd. The 

 five days showed a motion of 4'5°, or 0-9° a day, equivalent 



