Volcatws and Earthquakes. 67 



From Leop. Von Buch's instructive exposition of the nature 

 of volcanic phenomena,* which, together wiih the careful works of 

 Von Hoff, contain a critical compilation of all cases yet known of 

 the production of new mountains and islands by volcanic action, 

 we will borrow only the following examples of recent date. The 

 first I shall mention is the island of Sabrina, near St Miguel, 

 in the Azores, which is celebrated for the many islands that 

 have attempted to rise in its vicinity, and which made its 

 appearance on the 13th or 15th June 1811 ; it began to dis- 

 appear in October, and towards the end of February 1812, 

 steam was only occasionally seen to rise out of the sea at the 

 spot where the island was formerly seen.*|* Secondly, The 

 rising of a new island near Unalaschka, in May 1796, which 

 not only remained, but, up to 1806, had increased in cir- 

 cumference, as well as the peak in height. It required six 

 hours to row round it, and rather more than five hours to 

 ascend in a direct line from the shore to the summit of the 

 peak.J The creation of both these islands was preceded by 

 violent earthquakes, and columns of smoke, which ascended 

 from the sea, whilst stones were thrown to a great distance. Of 

 Sabrina this surprising circumstance is related — that the stones, 

 on leaving the sea, were black, but suddenly became red hot 

 when they emerged from the columns of smoke. Tillard found 

 on this island the skeleton of a shark so calcined, that the bones 

 fell to powder on lifting it up. Of the other island it is only 

 said, that during the night fire rose, which was sometimes so 

 bright, that all objects were distinctly visible in Unalaschka, at 

 a distance of twenty leagues. Smoke continued to rise for four 

 years. 



Phenomena of this kind have taken place still more recently 

 among the Molucca Isles, as we are informed by Prof. Rein- 



'' PoggendorfF's Ann. v. x. p. 1 and following, p. 169, 345, and 514 and 

 foUoAving. 



t See also V. Humboldt's Keise, t. i. p. 254, and t. iii. p. 6. It is worthy 

 of remark, that the small island of 1720 has reached exactly the same height 

 as Sabrina attained in 1811. 



X It was, consequently, more than 1000 feet high. Unfortimately the 

 depth of the sea at that place is not given. But it certainly offers an ex- 

 ample of one of the greatest elevations of the present day. 



e2 



