HOT FOUNTAINS OF THE AZORES. 305 



fluid. The congelation being sudden, and from all points at 

 once, would be of that kind which chemists call confused crys- 

 tallization j forming an opake mass, and including the impuri- 

 ties of the liquid in its substance. But the water over the body The water 



. , . , , .j A over the body 



being warmer, would not congeal at so early a period, except won ] ( j f rt , e «. 



with regard to a few spiculae, which would shoot into it from more slowly, 

 the surrounding ice, and form the white border of the figure j w j lite i> ort i er 

 and when at last its surface became gradually cooled down to the to the outline, 

 freezing point, this water would freeze, not all at once, but by a jJanMce 1 " 

 slow crystallization, from the edge inwards ; which is the very within, 

 process for making clear ice, used by Achaed, id his electrical ex- 

 periments, and is known to exclude all air bubbles, and mecha- 

 nical mixtures of impurity from the crystals. 



These effects, indeed, suppose a concurrence of favourable The effects Te- 

 circumstances which may rarely take place, but really appear <! urrem . e of 

 to have met in this uncommon case, and seem to support the cirenm- 

 preceding explanation even in the minuter particulars. Thus^*™^" 

 the abrupt termination of the head of the figure, agreeing with have taken 

 the lower part of the hat, leads us to an inference, that the aJ^co'nfirmcd 

 warmed water either found its way from under the hat, instead by the minor 

 of rising from its upper border, or that the felt acted as a bad incKlcnts - 

 conductor of heat, to the surrounding water : and the remark- 

 ably smooth slippery face of the ice of the figure, clear of 

 snow, while the rest of the ice was rougher and covered with 

 snow, should indicate that the rough ice was sufficiently cold to 

 protect its snow from thawing by the day temperature, which in 

 fact was above freezing ; while the ice of the figure, though 

 covered with snow on the 1 1th or 12th, was not so cold as to 

 prevent that snow from melting in the day time, and again 

 freezing in the night, with that very smooth and slippery 

 surface which is noticed in the description. 



X. 



Of the Caldeiras or hot fountains of the Furnas in the Island of 

 St. Michael, one of the Azores. 



PLATE VII. is taken, by permission, from !' the History of 

 the Azores," an entertaining work lately published, 

 respecting a part of the globe but little at (ended to. The 

 author's account of this phenomenon, states, thai the columns of 

 water are of very considerable diameter, and are thrown up to 



th« 



