16 
POPULAR SCIENCE REVIEW. 
Newfoundland. The best observed have performed this whole 
path in a time varying from seven to ten days. They have 
sometimes been only partially traced, and in some of these cases 
the rate has been much more rapid. Some few have gone in a 
straight line towards Mexico. In these storms the path of the 
centre of the storm is always from the equator into the north 
temperate zone, but the whirl itself moves from north by west 
to south, and round from south by east to north, being the re- 
verse direction to that of the hands of a watch. The diameter 
of the whirl, at first small, has gradually increased, the 
strength of the storm at the same time diminishing.* Thus 
the greatest intensity of each storm is near the centre of the 
whorl, and near the commencement of the path, and there of 
course are the most disastrous results produced. The smaller 
whorls of some great storms have not been more than 50 
miles in diameter at first, but have increased to 500 miles. 
Others have been more uniform. 
The limit of space occupied by these storms has been proved 
by the examination of the logs of ships in various positions, 
some within and others just outside the limit of the storm, and 
sometimes by the effect produced on land. The nature of the 
spiral motion is detected, and the magnitude of the spiral esti- 
mated, by the mode in which the storm returns to the same 
spot, and the very different quarter from which the wind blows 
within very short intervals. This is a characteristic of cyclonic 
storms ; and a knowledge of the fact and its cause is extremely 
useful to shipmasters, enabling them in some cases to avoid 
altogether the storm, in others to steer out of it with little 
damage, while other ships less intelligently conducted have 
suffered serious injury or been entirely wrecked. 
Few things are more remarkable than the exact repetition of 
the phenomena of great West Indian hurricanes. Tbis has 
been shown by an example quoted at the commencement of 
this article. The following outlines, derived from recorded narra- 
tives of characteristic examples, will serve as a general account. 
Before the storm the weather is fine, clear, and excessively hot, 
with light shifting winds and a high barometer ; if at sea the 
water is smooth. Suddenly the barometer falls, sometimes very 
much and very rapidly, at other times moderately, but almost 
always rapidly, and often some hours previously to change. 
The direction of the wind when the storm arrives depends on 
the part of the storm that first reaches the place ; but it shifts 
rapidly and soon veers, in all cases backing round from east by 
* This is not always the case, as in the great Barhadoes hurricane of 
1837 the path of the storni. at Barhadoes was about 130 miles wide, and 
had not increased to 200 miles when near Florida, a distance of nearly 
1,500 miles. 
