296 The American Geologist. May, 1897 
ing the history of the islands are as follows: the present land 
area was formed during a period of elevation, during which 
the entire archipelago was apparently a connected ])iece of 
hind. The elevation was probablj'^ not less thun seventy or 
eighty feet, and ma}' have been considerably more. The ele- 
vation was followed by a subsidence of at least 00-70 feet 
causing the lagoons and sounds. 
The last description of the Bermudas is that of Alexander 
Agassiz.* He accepts the iJiolian explanation for the hills and 
the theory of subsidence to account for the present dissected 
condition of the islands. He also believes in iniich erosion, 
but in the base rock he finds no proof of former greater eleva- 
tion as Rice has argued. He therefore holds to a single sub- 
sidence of the land since the formation of the sand hills. 
General Features of the Islands. The Bermuda islands, 
one or two hundred in number, are clustered together in a 
group, curved somewhat in the manner of a fish-hook. The 
length of the archipelago is about fifteen miles and the width 
about three. In size they vary greatly from the irregular, 
deeply indented main island, whose area is about 10,000 acres, 
to tin}'^ rocks in the sea. The greatest elevation above sea 
level is about two hundred and fifty feet, and a number of 
hills rise to the elevation of more than one hundred and fifty 
feet above sea level. 
This group of island> is situated upf)n the nearl}' level top 
of a peak which rises from the sea bottom, whose depth is 
twelve to fourteen hundred fathoms at a distance of only 
eight or ten miles from the edge. The peak has the form of a 
volcanic cone, which probably it is, smoothed over at the top. 
The shallow top of the peak is a reef-covered and somewhat 
irregular shoal, elliptical in outline, with diameters of about 
twenty-five and twelve miles. The depth of water upon this 
shallow, reef-like plain is rarely over eight or nine fathoms. 
The islands which are set upon this are mainly clustered at 
the southern and southeastern side of the shoal. South of 
this are two other banks smaller in area, but deeper below 
the surface of the sea. 
*Bull. Mus. Comp. ZooL, xxvi, No. 2, 1895, 209-281. A shorter state- 
ment of the same observations was made in the Amer. Journ. Sci., 
xLvii, 1894, 411-416. 
