^88 Analysis of Air Scoresbys Account 
they may be, never for one moment loses sight of his piinch 
pal object, which is the improvement of navigation ; he unfolds 
the dangers to which ships are exposed, and teaches the means 
of extricating them ; he determines the limits which the ices 
occupy in different seasons, and points out the times of the year 
when certain latitudes should be frequented in preference to 
others, without omitting what experience has taught us regard- 
ing the variations those limits may undergo in the same season. 
The reciprocal effects of ice of a certain extent on the atmo- 
sphere, and of the atmosphere on the ice, have not escaped the 
inquiring mind of Mr Scoresby. From these he has deduced 
arguments, which very naturally explain how strong gales, and 
even violent storms, occupy so small an extent in icy seas, that 
if several vessels be separated from each other, but yet in 
sight, some may be impelled by an impetuous gale, while others 
are becalmed, or have only a moderate breeze. All the pheno- 
mena are discussed with clearness, and lead our author to an ex- 
amination of the grand question. Whether it be possible to find 
a navigable sea to the North Pole ; and he inclines to the opi- 
nion of those who are sceptical on the subject : 1^^, He grounds 
this belief on the general principle, that effects should augment 
with the intensity of the causes which produce them ; 2d, On 
the experience of the multitude of vessels, for many ages, em- 
ployed in the Whale-fishery in high latitudes, which have ah 
ways met with an icy barrier, of which the limits, indeed, are 
more or less distant, but which has never been passed beyond 
the 82d parallel of latitude. 
The subjects of the four first chapters are immediately inte- 
resting to navigation ; some of them have never before been 
systematically treated ; and if they have been occasionally intro- 
duced, it has only been as the subject of isolated reflections : But 
in this work, all the facts which relate to the same phenomenon 
are brought together; and the author, not confining himself to 
a j;Y'^;ffj9us deduction of causes from their effects, frequently un- 
ravels, with much sagacity, the modifications of which both are 
susceptible. 
His general method of procedure is an example of what may 
be accomplished by deliberate experience, aided by solid infor- 
mation ; and it would be very advantageous to make it known 
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