298 ANNUAL OF SCIENTIFIC DISCOVERY. 



reached the same points, traveling through shallower water. The calcula- 

 tions based on these data give for the Pacific Ocean a depth of from 14,000 to 

 18,000 fathoms. It is remarkable how the estimates of the ocean's depth 

 have grown less. La Place assumed it at 10 miles, "Whewell at 3*5, while 

 this estimate brings it down to about 2 miles. 



At a recent meeting of the Asiatic Society, China, Dr. Macgowan read a 

 paper on recent Physical Phenomena in China and Japan. The communica- 

 tion related to the earthquake at Simocla, which appears in many of its features 

 to have resembled that which destroyed Lisbon in 1775, when the lakes of 

 Scotland were suddenly elevated, and the sea at Madeira rose to a prodigious 

 height. Thus, the late earthquake at Japan was followed by a rise of the 

 inland waters of Chihkiang in China, and by an extraordinary receding and 

 subsequent elevation of the sea at the Benin Islands. The appearance of 

 "white hairs," as the.v are styled by natives, following earthquakes in China, 

 was alluded to ; and it was suggested that they are a salt formed by the 

 emission of vapor and sulphuric acid coming in contact probably with alumina 

 in the earth. Notice was made also of the rise and subsidence of a volcanic 

 !slay 1 near Formosa in 1854, and of showers of dust in the China Sea. 



THE EKUPTIOX OF MOUNT VESUVIUS IN 1855. 



An inceresting report on the recent eruption of Vesuvius has been made 

 by Professor Palmieri of the Observatory of Naples. It appears that the 

 magnetic needles, which had been slightly affected on the 29th of April, were 

 greatly agitated on the 30th; and on the following day the eruption broke 

 out. No fewer than ten craters opened in the course of a few hours, followed 

 by many smaller ones, all throwing out lava and heated stones, accompanied 

 by subterranean thunders and ruddy masses of smoke. These streams, de- 

 scending into the plain, called the Atrio del Cavallo, formed there a sea of 

 fire, whose shores were on either side the mountain of Somma and the lavi 

 of 1850. Early in the progress of the eruption, the lava was 100 palms in 

 depth ; and it was considered that if another such an accumulation took 

 place, which certainly has now happened, the Hermitage and the Observatory 

 would be in danger. 



The magnetic apparatus of Lament was used by Professor Palmieri on the 

 occasion of the earthquake of Melfi ; and the results were such as to induce 

 him to think that it would not be mute, as the event has proved, on the oc- 

 casion of an eruption of a volcano. Anticipating, as it has done, such a 

 catastrophe by several clays, it is one of the most beautiful and convincing 

 proofs of the practical applicability of science to the service of human beings 

 that modern da}-s lias furnished us with. Passing from magnetism to elec- 

 tricity, Professor Palmieri says that on the first day of the eruption observa- 

 tions were impossible; but, on the clouds clearing off, he ascertained that 

 there was a great tension of positive electricity, which increased considerably 

 on the fall of some ashes on the evening" of the 2d inst. In general, the 

 electricity was always stronger when the wind blew toward the Observatory. 

 It manifested itself very vigorou.--.ly to ilv.; movable conuAK-IxT, net always to 



