August 13, 1896] 



NATURE 



345 



destruction of their hopes, and the next total solar eclipse 

 will be as eagerly looked forward ^to as the one just 

 hidden from them. 



An interesting description of the scene in the neigh- 

 bourhood of X'adso appeared in Tuesday's Times, and 

 the following is an abridgement of it. 



On Sunday morning the \"aranger l-'iorti in the north-east of 

 Norway presented a scene which has probably never before 

 been eciualled in a latitude of 70'. The anchorage at the port 

 of Vadsii was crowded with nien-ofwar, yachts, and passenger 

 steamers, lirought together by reason of the total solar eclipse. 

 For several days the numerous astronomers on these ships have 

 been engaged in landing their delicate and elaborate instru- 

 ments, and transporting them to the beautiful sites which here 

 abound. 



By last night the laborious preparations of the diflerent 

 observing parties had been completed, and they awaited with 

 what composure they might the momentous events of the 

 morrow. In any circumstances an Arctic summer night, where 

 broad daylight reigns throughout, is very different from a night 

 in a temperate region. But on this occasion there were so many 

 interruptions, partly by the arrival of friends in the various 

 ships, that rest was but little thought of, and indeed from two 

 to five and even earher a succession of boats brought hundreds 

 of passengers from the ships to the shore. 



The fence which marked out the ground occupied by the 

 observers was guarded by bluejackets, charged with the duty of 

 keeping at a suitable distance the groups of picturesquely-clad 

 Finns and Lapps, who gazed with astonishment on the strangers 

 who had travelled so far, and on the wonderful appliances they 

 had brought with them. Many of these .\rctic inhabitants were, 

 however, sufficiently sophisticated to be provided with the 

 traditional pieces of smoked glass with « hich to make their own 

 observations. 



The sun could not be seen at the moment when the moon 

 first made contact, though almost immediately afterwards it was 

 visible with a slight encroachment on the brilliant edge, showing 

 that the eclipse had commenced. For nearly an hour hope and 

 fear then alternated. Everything, of course, depended on the 

 condition of the sky at the niomenl of totality, and it was hoped 

 that some of the characteristic phenomena of a total eclipse 

 might be jiresented. This hope was strengthened as the 

 crescent sun waned thinner and thinner and still remained 

 visible. 



As the supreme moment of totality approached, the broad 

 landscape .sensibly darkened, and the fiord became more gloomy. 

 It was as if some mighty thunder-shower was about to descend; 

 but, alas ! the clouds again thickened, and the observation of the 

 moment of actual totality, if effective at all, could only be made 

 by glimpses with a telescope through a very dense medium. Some 

 observers were, of course, constrained to limit their attention to 

 their instruments, and to the sole discharge of the duties which 

 had been entrusted to them. But many were in the position of 

 being able to look at the sun until the crescent of light was about 

 to disappear, and then face round to the opposite point of the 

 horizon. The object of this manceuvre was to permit the observer 

 to .see the impressive spectacle of the advance of the lunar shadow 

 over the earth. 



The situation at Vadso lent itself admirably to the observation 

 of this magnificent phenomenon. As the shadow advanced 

 across the fiord, it enveloped the training squadron as it lay at 

 anchor, the details of the ships' rigging disappeared from view, 

 and their lights gleamed forth brilliantly. Still the shadow 

 pressed on with its majestic speed of a mile in every couple of 

 seconds. It moved as swiftly as a cannon-ball until it reached 

 the observers at Vadso, and then announced to them in the most 

 impressive manner that tlie supreme moment of their visit had 

 arrived, and that totality was complete. 



The darkness that then buried Vadsii and its numerous ob- 

 servers lasted for a minute and forty seconds. The unwonted 

 spectacle hushed every one to silence. A few startled birds 

 hurried past the camp, and amid the canopy of cloud which 

 covered the heavens at least one observer descried a star. But, 

 though all the visitors felt that the magnificent phenomena were 

 worthy of being remembered as a life-long experience, yet it is 

 none the less true that, from a scientific point of view, the 

 result of all the labours at Vadso was hardly anything. 



The object of the astronomers, who erected at such vast pains 

 great photographic instruments, was to depict the corona and to 



NO. 1398, VOL. 54] 



analyse with spectroscopes the light which it dispenses. It is 

 true that during the time of totality they e.xposed their plates in 

 accordance with the careful drill and organisation which were 

 indispensable if full advantage was to be taken of the brief 

 period. But, unfortunately, during the time of totality the 

 clouds were obdurate, and nothing could be seen. The innumer- 

 able telescopes directed to the sun showed no more than the 

 same instruments would have done if they remained still 

 covered. 



The 100 seconds fled, marked only by the mechanical pre- 

 cision of the officer who counted them aloud. The astronomers 

 might safely spare glances to the interesting view over land and 

 sea. The light around them was not greater than that during a 

 full moon, but in the distance mountain-tops could be descried 

 which were not in the shadow and were shining brilliantly. 



At last the darkness lifted, and the manner in which the light 

 returned was almost startling in its suddenness. It was not that 

 the sun became visible — this, indeed, did not at first happen — 

 but when the moon had passed by, and when totality was over, 

 the sun illumined the clouds, and this gave again the usual 

 light of cloudy day when the orb itself is invisible. A few 

 seconds later a glimpse was afforded of the crescent form of the 

 sun, and then the clouds closed in once more, and did not with- 

 draw until long after the moon had passed away from the disc. 



THE PHYSICAL LABORATORY AT LEIDEN 

 {HOLLAND). 



WHEN a few years ago it appeared advisable to Prof 

 Kamerlingh Onnes, the IJirector of the Physical 

 Laboratory at the University of Leiden, to start the issue 

 of a periodical paper which would contain a regular 

 account of the research work that was going on in his 

 laboratory, he decided upon the English language as being 

 for various reasons the most suitable for the purpose. 

 The " Communications from the Physical Laboratory at 

 the University of Leiden " consist, as a rule, of more or 

 less happy tianslations of contributions by Prof. Onnes 

 and his pupils to the Proceedings of the " Koninklijke 

 Akademie" of Amsterdam. They give short accounts of 

 the researches that are carried out, and contain theoretical . 

 notes, as a rule, in direct connection with the experimental 

 work. The full accounts of the investigations are mostly 

 to be found elsewhere in various French, German or 

 English periodicals.' No. 23 of the series appeared 

 lately, and the whole set, containing everything that has 

 been done in the laboratory since 18S5, is now complete. 



The most important characteristic which distinguishes 

 the Leiden laboratory from most of its contemporaries 

 is its installation for high-pressure and low temperature 

 work. There are probably only one or two more places 

 where an installation of this kind is permanently joined 

 to a well-provided physical laboratory. Nos. 14 and 23 

 (especially the former) give a general idea of its gradual 

 development and present arrangement. 



Ever since 1883 Prof. Onnes has been working at this 

 department. His object was in the first place to develop 

 and improve the methods introduced by Cailletet, Pictet, 

 Wroblewski, Olszewski, and to prepare larger quantities 

 of liquid oxygen than before, so as to be able to decant it 

 and use it as a cooling agent for experiments, especially 

 on the liquefaction of hydrogen. The same object was, 

 during the same years, striven after by Pictet, Olszewski 

 and, in this country, by Dewar. Owing to want of sufficient 

 funds and personal assistance, the work progressed very 

 slowly, and it was not till June 1892, that a small quantity of 

 liquid oxygen was decanted, while in December 1893 half 

 a litre was obtained. It is interesting to notice how entirely 

 independent the Leiden work is from the others. In the 

 first place, Prof Onnes uses Pictet's cycle method, while 

 Olszewski developed the method used by Wroblewski in 

 conjunction with himself Instead of sulphurous acid, 

 used by Pictet, he introduced methylchloride in the first 

 cycle (a suggestion of Cailletet's), while ethylene remained 



1 Archives SicrlandaiscSy Wkdciiianiis Annalen, Bcibliittcr, Zeit- 

 schri/t fur PlivukatUchc Chcmk, Fhilosciphkal Magazine. 



