CATARACTS, AND INUNDATIONS. 143 



consequent ebullition during these recurrences, that its waters are 

 projected in a jet-d'eauof not less than from five to ten fathoms of 

 perpendicular height. The tides of the hot-springs at Rykum, for 

 there are several, are renewed still more frequently; often, in- 

 deed, not less than two or three times in the course of a quarter 

 of an hour. The very curious hot spring described by Captain 

 Billings (Expedition to the Northern Parts of Russia) near the 

 volcano of Opabk in Kamscatka, is so incessantly supplied with sub- 

 terranean heat, as to be permanently ebullient. It is very extraordi-. 

 nary that the ice in the celebrated cavern of Grace-Dieu, is plen- 

 tiful and solid during the summer, and almost wholly wasted in the 

 winter season. M. Cadet, in a paper inserted in the Annales de 

 Chymie, vol. xlvi. has endeavoured to account for this anomaly, by 

 the increase of cold produced by the evaporation from the moist 

 and massy foliage that surrounds the cavern during the summer 

 months. He has here, perhaps, given us the real cause of the va- 

 riation in the temperature of the fountain before us, but it is a cause 

 scarcely adequate to the production of ice in summer, though it 

 mny make a warm stream colder in the day time than at night." 



To this full and explicit account we shall only add the two fol- 

 lowing coincident facts. " In the midst of the river Men, south of 

 Peterborough in Northamptonshire,** says the humourous and enter- 

 prising Isaac Walton, " is a deep gulph called Medeswell, so cold 

 that in summer no swimmer is able to endure it, yet it is not frozen 

 in the winter." And Mr. Wales, in his Journal of a thirteen month** 

 residence on the north-west coast of Hudson's Bay, which we shall 

 more particularly advert to in a subsequent chapter, tells us, that 

 when he was staying at one of the hunter's tents for about a week in 

 the month of December, he was told that there was a spring very 

 near them, which was not yet froyen over, though the sea was frozen 

 up as far as could be seen, and the ice in the river was four or five 

 feet thick. He wrnt to see it: but that morning the frost had 

 been so intense, that it. was frozen over about an inch thick. He 

 broke the ice, and, to his surprize, found the water so shallow, that 

 the mud was immediately raised from the bottom by the act of 

 breaking it. The adjoining springs, that were at least six times its 

 depth, had 'at this period been frozen quite dry for several weeks. 

 \Ve regret that Mr. Wales has ivcn us no account of the actual tem,- 

 perature or the mineral principles of this singular well. 



EDITOR* 



