130 Part IL, Chapter 2. 
Low rounded hills are seen, typic sand dunes, more rugged on the leeward 
side. :The rock is honeycombed by the weather and is called eolian, and is 
extremely porous the rain water rapidly percolating through. The Bahamas 
with the exception of Andros island are destitute of springs, or running streams, 
the water collecting in underground reservoirs. 
g. The Bermudas. 
This small group of islands stands on a marine bed 25 miles long in 
latitude 32° 20’ N. and longitude 64° 50’ W. about 600 miles (965 km) E. by 
S. from Cape Hatteras on the American coast. All are of coralline formation 
and the Bermuda archipelago marks the northern limit of the coral. building 
polyps. The reefs encircling the islands are still growing and leave a few 
intricate passages where ships can enter. The largest of these islands is Long 
Island enclosing on the east Harrington, or Little Sound and on the west Great 
Sound, studded with islets. Boaz, Somerset and Ireland islands protect Great 
Sound on the north. St. David’s, Smith’s, Cooper’s, Nonsuch, St. George’s and 
Paget’s islands lie to the east and form a crescent about Castle Harbor. 
White granular limestones of various degrees of hardness with caves eaten 
into them constitute the geologic material of these islands.. The rocks have 
been formed from wind blown calcareous sand heaped into dunes, which have 
been consolidated into a porous limestone by the cementing action of rain- 
water, containing carbon dioxide. By subsequent erosion, soil has been formed 
from these rocks (usually of a red character), as a one percent residue left 
after the removal of the limy salts. It represents peroxide of iron, silica and 
' earthy phosphates, sparingly soluble in water. Stream and wells of fresh water 
are entirely wanting and the people are dependent on the rain water, which 
they collect and preserve in tanks. 
Chapter II. Climate of North America. 
General remarks. In dealing with the climate of North America in general, 
we must consider it from the continental aspect. It is important, therefore, 
to give a brief summary of the peculiarities of the climatology of large con- 
tinents before the tables and data of temperature, precipitation and other 
meteorologic phenomena are presented. 
A common feature of continental climates in all latitudes is their large range 
of temperature. Marine climates, including those of oceanic islands, on the 
other hand are characterized by a small annual range. A continental climate 
is, therefore, considered to be severe as regards its temperature conditions, 
while a marine climate is mild by contrast. The annual temperature curve of 
continental and marine climates is of a different type. In continental climates, 
the maximum temperature comes about one month after the date of the sun’S 
maximum altitude, while the minimum temperature is similarly, though to 4 
u 2 10 re 
ENT, se = 
NEN REES ER RR  AE WERNTER I HR 
