34 MEMOIR OF 



after four, the water flowed over very strongly 

 during the space of a minute ; in six minutes 

 after, we heard many loud subterraneous dis- 

 charges, not only near the spring, but also from 

 the neighbouring ridge of rocks, where the water 

 spouted ; at fifty-one minutes after six, the fountain 

 spouted up to the height of ninety-two feet, and 

 continued to do so for four minutes. After this 

 great effort it sank down very low into the pipe, 

 and was entirely quiet during several minutes, 

 but soon began to bubble again ; it was not, how- 

 ever, thrown up into the air, but only to the top 

 of the pipe.* The force of the vapours which 

 throw up these waters is excessive : it not only 

 prevents the stones which are thrown into the 

 opening from sinking, but even throws them up 

 to a very great height, together with the water. 

 When the basin was full, we placed ourselves 



* From observations that have been made at different 

 periods, it appears that the height of the jets is very 

 irregular. In Olafsen's time it is stated to have been 

 three hundred and sixty feet. The highest above stated, 

 in 1772, was ninety-two feet. Sir John Stanley, in 1789, 

 gives ninety-six feet ; Lieutenant Ohlson, a Danish officer, 

 found, by a quadrant, that the highest jet ran, in 1804, to 

 two hundred and twelve feet ; Mr Hooker, in 1809, men- 

 tions one hundred feet; and Sir George M'Kenzie, in 1810, 

 states it to have been ninety feet. Henderson, in July, 

 1814, saw it vary from sixty to a hundred feet, and again, 

 in August, 1815, it was one hundred and fifty feet. 



