THE EQUATORIAL CLOUD-RING. 
173 
lation by the continual flapping of the ship's sails, it would be al- 
most insufferable. No person who has not crossed this region 
can form an adequate idea of its unpleasant effects. You feel a 
degree of lassitude unconquerable, which not even the sea-bathing, 
which every where else proves so salutary and renovating, can 
dispel. Except when in actual danger of shipwreck, I never spent 
twelve more disagreeable days in the professional part of my life 
than in these calm latitudes. 
"I crossed the line on the 17th of January, at eight A. M., in 
longitude 21° 20^, and soon found I had surmounted all the difficul- 
ties consequent to that event ; that the breeze continued to freshen 
and draw round to the south-southeast, bringing with it a clear 
sky and most heavenly temperature, renovating and refreshing be- 
yond description. Nothing was now to be seen but cheerful coun- 
tenances, exchanged as by enchantment from that sleepy sluggish- 
ness which had borne us all down for the last two weeks." 
349. One need not go to sea to perceive the grand work which 
the clouds perform in collecting moisture from the crystal vaults 
of the sky, in sprinkling it upon the fields, and making the hills 
glad with showers of rain. Winter and summer, "the clouds drop 
fatness upon the earth." This part of their office is obvious to all, 
and I do not propose to consider it now. But the sailor at sea ob- 
serves phenomena and witnesses operations in the terrestrial 
economy which tell him that, in the beautiful and exquisite ad- 
justments of the grand machinery of the atmosphere, the clouds 
have other important offices to perform besides those merely of 
dispensing showers, of producing the rains, and of weaving man- 
tles of snow for the protection of our fields in winter. As import- 
ant as are these offices, the philosophical mariner, as he changes 
his sky, is reminded that the clouds have commandments to ful- 
fill, which, though less obvious, are not therefore the less benign 
in their influences, or the less worthy of his notice. He beholds 
them at work in moderating the extremes of heat and cold, and in 
mitigating climates. At one time they spread themselves out ; 
they cover the earth as with a mantle ; they prevent radiation 
from its crust, and keep it warm. At another time, they interpose 
between it and the sun ; they screen it from his scorching rays, 
and protect the tender plants from his heat, the land from the 
drought ; or, like a garment, they overshadow the sea, defending its 
