444 
VOYAGE OP THE POTOMAC, 
[December, 
with five lofty arches. The bridge is provided with seats, and is 
a fine lounging-place in summer evenings. 
There are numerous small fountains ; a principal one in the 
Plaza throws up the water many feet above the surface of the 
ground. 
The atmosphere of Lima is almost uniformly dark and murky. 
The smoke of the city, the vapour from the coast, and the exha- 
lations from a rich vegetation, perpetually overhang the city like 
a wide-spread awning, which the gentle force of the south wind, 
the only one to which it is exposed, is not able to raise above the 
summits of the surrounding hills. Even in the season of greatest 
heat, when the sun approaches the zenith, rarefying the air and 
dispelling the vapours, the mist still shrouds the city, while the 
surrounding country, at no great distance, enjoys a clear and 
beautiful sky. If, during the clearest weather, a passing cloud 
intercepts the rays of the sun, a condensation of the vapours 
immediately takes place, and the sky is at once overcast, showing 
the great amount of moisture in the atmosphere. Throughout 
the day, in the winter season, the atmosphere is in continual com- 
motion. In the morning the horizon is covered with dense fogs : 
these soon rise and disperse as the sun advances ; and at noon it 
is clear, and the sun can be seen : in the evening the fogs return 
again and settle on the earth. In the winter there are some clear 
days and moonlight nights, but these are rare. These nights, 
however, present the heavens among the most beautiful in the 
world. There are found above the horizon, Orion, the Dogs, the 
Ship of Argo, and the beautiful constellation of the southern 
Centaur. If we except those days at the end of the warm season 
when the sun is most powerful, and" others in the winter when he 
is most obscured by clouds, every day for the rest of the year 
will be little else than an alternation of light and shade : the pro- 
portion between the two varying according as the sun approaches 
or departs from the southern tropic. In the first instance, the 
rays of the sun being more direct, have more force, and efficacy 
in dispelling the clouds; while their obliquity in the latter case 
renders them less efficient. Hence, this perpetual conflict and 
alternate ascendency of the vapours and the rays of the sun, 
gives Lima a hot and humid climate, without any of the extremes 
of these temperaments. 
