344 THE OCEAN. 
canvas can be secured, the gale is howling shrilly 
through the spars and rigging, and the crests of 
the waves are torn off, and driven in sheets of spray 
across the decks. The lightning is terrible: at very 
short intervals the whole space between heaven and 
earth is filled with vivid flame, showing every rope 
and spar in the darkest night as distinctly as in the 
broadest sunshine, and then leaving the sight ob- 
scured in pitchy darkness for several seconds after 
each flash; darkness the most intense and absolute; 
not that of the night, but the effect of the blinding 
glare upon the eye. The thunder, too, peals now 
in loud, sharp, startling explosions, now in long mut- 
tered growls all around the horizon. In the height 
of the gale, curious electrical lights, called St. Ulmo’s 
fires, are seen on the projecting points of the masts 
and upper spars, appearing from the deck like dim 
stars. Soon after their appearance the gale abates, 
and presently clears away with a rapidity equal to 
that which marked its approach. 
The storms are found, by carefully comparing 
the directions of the wind at the same time in dif- 
ferent places, or successively at the same place, to 
blow in a vast circle around a centre: a fact of the 
utmost importance, as an acquaintance with this 
law will frequently enable the mariner so to deter- 
‘mine the course of his ship, as to steer out of the. 
circle, and consequently out of the danger; when, 
in ignorance, he might have sustained the whole 
fury of the tempest. The course of the circle is the 
opposite of that taken by the hands of a watch, and 
is the same with that of the still more striking phe- 
