[BARNES] ANCHOR-ICE FORMATION 75 



The thermometer in the open air stood at — 12° centigr. 

 The "water in the river at every depth was at zero cent. The ice at 

 the bottom was only formed in places, however, where there were stoneg 

 and angular stuff. It was spongy, and' formed of icy spicula. 



The overseers of the bridge stated that it never appeared on the 

 surface until after 10 or 11 o'clock in the morning. 



The canal of Saint-Alban conveys the waters of the Birse through 

 the town of Bale. It is very limpid and ilows with great rapidity. 

 During the winter of 1823, Professor Merian carefully examined the 

 bed of the canal, which, in general, is covered with pebbles, and saw 

 that wherever the bottom exhibited any projection, there was a small 

 piece of ice, which might have been supposed, at a distance, to be a 

 Teuniting of tufts of cotton. This ice becaiTje disengaged from the 

 bottom from time to time, and floated on the surface. It had all 

 the appearance of the grund-eis of the German watermen. 



M. Hugi, president of the Société d'Histoire Naturelle de Soleure, 

 is the philosopher who, in my opinion, has seen the phenomenon of the 

 formation of ice at the bottom of water displayed on the greatest scale. 

 His first observations were made in 1827. 



From the 2nd to the 3rd February of that year, the river Aar, 

 at Soleure, was breaking up the ice; on the 15th it was completely 

 open. It flowed slowly on the 16th, and the water was perfectly pure. 

 On this day, in consequence of a westerly wind, a multitude of large 

 icy tables were continually rising from the bottom about 60 or 70 

 feet below the bridge, and over a surface of upwards of 450 square 

 feet. I ought to add, as this circumstance confirms what Hales was 

 told by the fishermen of the Thames, that the great proportion of the 

 flakes of ice mounted vertically, till 5 or 6 decimetres above the sur- 

 face of the water, and after remaining a few minutes in this position, 

 they sunk down, and floated horizontally. 



After a certain time, the flakes of ice became more scarce; but 

 they had increased to such an extent, that many, though almost vertically 

 raised above the water, still rested in the bed of the river on one of 

 their sides, and in which position they remained stationary for a long 

 time. The phenomenon lasted for about a couple of hours. 



Below the bridge, the Aar flows with rapidity over an inclined 

 channel of 20 to 30 degrees, and in many places is quite stony. Be- 

 yond the place where the flakes of ice arose, the water, already more 

 tranquil, always exhibited a sort of eddy. 



The temperature of the air was — 5°. 7 centig. ; near the water 

 — 4°. 9; close to the surface of the river, -|-2<^.l. The water near tlie 

 arches, where there was no ice, was at -}-3°.0; at the bottom, where 

 ice ascended, 0°.0. 



