20 REPORT—1858. 
the Cape de Verds, the West India Islands, and the great submarine volcanic 
region first noticed by M. Daussy, besides many other points, as Ascension, 
St. Helena, St. Paul’s, &c., at which extinct volcanic phenomena are visible. 
The number of observations, however, as yet recorded of earthquake-shocks 
within the basin is so very small, that Perrey has been only able to collect from 
130 to 140 instances between the years 1430 and 1847, or about three a 
year on the average; so that he does not deem the basis large enough to 
warrant any numerical discussion. The observations of M. Daussy, “ Sur 
l’existence probable d’un volean sousmarin situé par environ 0° 20! de lat. 
S. et 22° 0' de lon. ouest,” published in vol. vi. p. 512, ‘Comptes Rendus 
de l’Académie’ (1853), have, however, made this one of the most interesting 
seismic regions on the globe. 
M. Moreau de Jonnés (‘Comptes Rendus,’ vol. vi. p. 302) has given two 
recorded observations on board French ships, the ‘Czesar’ and the ¢ Syl- 
phide,’ which render the existence of a submarine volcanic tract on the bank 
of Bahama highly probable; but M. Daussy has collected and given obser- 
vations of shocks received by vessels at sea at various periods, but all within 
a given limited area, which renders the existence almost certain of a vast 
active volcanic suboceanic area in the basin of the Atlantic, nearly midway 
between Cape Palmas on the west coast of Africa, and Cape St. Roque on 
the east coast of South America, or in the narrowest part of the ocean between 
these continents. This vast disturbed and perhaps partially igneous ocean- 
floor can be no less than nine degrees in length from west to east, and from 
three to four degrees in breadth from north to south. The following are the 
observations given by Daussy; and the relative positions of the several 
recording ships are given in the diagram (fig. A.) :— 
17th Oct. 174’7.—The ship ‘ Le Prince,’ Bobriant: twoshocks. Lat. 1° 35’ S.; 
long. 20° 10’ W. 
5th Feb. 1'754.—The ship ‘ Silhouette,’ Pintaul: one shock, with trembling. 
Lat. 0° 20’ S.; long. 23° 10! W. 
13th April 1758.—The frigate ‘ Fidéle,” Lehoux: several shocks. Lat. 
0° 20' S.; long. 23° 10! W. 
3rd May 1761.—The ship ‘ Le Vaillant,’ Bouvet: saw an islet of sand above 
water, in lat. 0° 23! S. and long. 21° 30’ W. 
3rd Oct. 1771.—The frigate ‘Le Pacifique,’ Bonfil: one shock and trem- 
bling. Lat. 0° 42'S., and long. by estimation, 22°47 W. An agi- 
tated sea, and no bottom found on sounding. 
19th May 1806.—M. de Krusenstern (ship’s name not given). Lat. 2° 43' S., 
and long. 22°55! W. Saw columns of smoke twelve or fifteen miles 
to the N.N.W., which he and Dr. Horner attributed to voleanic sub- 
marine eruption. 
18th Dec. 1816.—The ship ‘The Triton,’ Proudfoot: in lat. 0° 23'S., and 
long. 20° 6! W., passed over a shoal of about three miles from east to 
west, and one mile from north to south. Twenty-six fathoms water, 
with bottom of brown sand. ; 
12th April 1831.—The ship ‘Eagle,’ J. Taylor: in lat. 0° 22’ S., and long. 
23° 27' W., the sea being perfectly calm; one violent shock: the rudder 
was powerfully shaken, and a muffled sound was heard from beneath. 
Nov. 1832.—The ship ‘La Seine,’ Le Maire: in lat. 0°29! S., and | 
Jong. 21° 15'W. Under easy sail; one powerful shock. 
9th Feb. 1835.—The barque ‘ The Crown,’ of Liverpool (captain’s name not 
given): lat.0°57'S., and long. 25°39! W. When going six knots, 
was thought suddenly to have struck on a coral rock and to have 
