June 12, 1879] 



NATURE 



153 



other and assuming various fantastic shapes. The total 

 surface of ice and rock is 8,874 square metres, that of the 

 oSer being 7t"7 1 squaremetres, of the latter 1,703 square 

 r^^res; the i^ass of the ice amounts to 125,000 cubic 



™The%avern consists of two parts, an upper and lower 

 stage • the former is reached immediately after leaving 

 the entrance, its floor being formed of ice, its roof and 

 walls of hmestone; it is partially divided into two unequal 

 chambers, the small and great saloons (Fig^i), by a 

 curtain of rock descending from the roof. The small 

 saloon is not situated on the same 

 level as the great saloon. In the 

 great saloon are three ice pillars 

 (Fig. I); they are translucent, and 

 down the cylindrical hollow of one 

 pillar there is a continuous though 

 small flow of water ; in addition 

 there are numerous other ice orna- 

 ments which have received fanciful 

 names. The eastern end of the 

 saloon is contracted into a very 

 narrow corner ; at this point there 

 has been a landshp corresponding 

 to a crater-shaped depression in the 

 slope of the Duosa Mountain, in 

 which the cavern is situated. In 

 the small saloon to the right of the 

 entrance is a waterfall composed 

 entirely of ice. 



The lower stage consists of a 

 corridor (Fig. 2) following the south 

 side wall of the saloon ; the down- 

 ward prolongation of the dome- 

 shaped rock wall of the saloon 

 forms the south corridor wall, while 

 the naturally formed cross-section 

 of the ice constitutes the northern. 

 The corridor originally consisted of 

 two portions, a right and left wing, 

 separated by a mass of ice; this 

 has now been bored through. The 

 entire length of the corridor is 200 

 metres. 



The right corridor wing is reached 

 from the small saloon by going 

 down a steep flight of steps through 

 a natural opening ; the mass of ice 

 whose upper surface forms the floor 

 of the saloon after touching the 

 roof suddenly terminates so as to 

 make a nearly vertical wall to the 

 corridor; the floor of the latter sinks 

 down into the depths below, ter- 

 minating in a mass of debris; this 

 point probably forms a natural 

 outlet for the water. 



In the left corridor-wing is a 

 magnificent ice structure termed 

 the Grotto (Fig. 3). ;_ 



The cooling of the air and the 

 permanent low temperature (the 

 mean of the year being - '86° C.) 

 of the cavern are due to its height 



and northern aspect, as well as to its narrow open- 

 ing and contracted exit canal, and to its floor gradually 

 sloping inwards; as a result of this, the water is con- 

 verted into ice, and the permanence of the latter thus 

 insured. 



Through the kindness of Herr Ruffiny, the discoverer, 

 and Dr. Pclech, I have been enabled to obtain the loan 

 of the woodcuts. 



W. Bezant Lowe 



THE VISITATION OF THE ROYAL 

 OBSERVATORY 



ON Saturday last the annual visitation of the Royal 

 Observatory was held, when the Astronomer-Royal 

 read his annual report, which refers to a period of 

 thirteen lunations, from the new moon of 1878, May 2, to 

 the new moon of 1879, May 20. We noti:e some of the 

 most important points in this report : — 



Considerable alterations have been made in the great 

 equatorial, so as to make the instrument easy for use with 

 the long half-prism spectroscope. The deilination axis 



Fig. 3.— The Grotto. 



■ being meridionally cxcentric by 14 inches as regards the 

 polar axis, the observing-chair may be made available tor 



1 eye-observations and for spectroscopic observations re- 

 spectively, by reversing the instrument in hour-angle S3 

 as to take advantage of this excentricity. 



With regard to the numerous group of minor planets, 

 the Berlin authorities have most kindly given attention to 

 the Astronomer- Royal's representation, and we have now 



\ a most admirable and comprehensive ephemeris. 



