CLIMATE. 23 
‘Dr. H. Gibbons, speaking of the mists and fogs at San Fran- 
cisco, says: 
“Tt is curious to observe the conflict between the absorbing 
power of the air and the supplying power of the ocean, in re- 
gard to moisture. Toward noon, when the wind rises, huge 
columns of mist may be seen piled along the coast, three or 
four miles west of the city, and pouring in like a deluge upon 
the land. But the air of the land, which is always thirsty, 
drinks it up with astonishing avidity; so that the impending 
wave, though in a current moving from thirty to fifty miles an 
hour, makes slow progress. By the middle of the afternoon 
it is within a mile or two of the city; and there it stands, like 
a solid mass of water several hundred feet in depth, rolling and 
tumbling toward you (not without grandeur and majesty), and 
threatening to overwhelm you in afew seconds. You await 
its coming, but it comes not; it even recedes, to return and 
recede again. Not until the sun has lost his calorific power 
does the atmosphere reach the point of saturation; and then, 
toward sunset or later, every thing is submerged by the va- 
pory flood. In the course of the evening the wind falls. Dur- 
ing the night the mist is gradually dissolved and disappears 
from the lower stratum of air, while it forms a heavy cloud 
above. About the middle of the forenoon the cloud is dis- 
persed by the rays of the sun. The dispersion is rapid, the 
sky often becoming entirely clear in less than half an hour. 
“Ifit be possible to distinguish between fog and mist—re- 
garding the former as impalpable, and the latter as composed 
of palpable particles of moisture—I may remark that mist be- 
longs only to the summer and fog to the winter climate of San 
Francisco. There is no mist in winter, and no fog in summer. 
At all seasons the drying tendency of the atmosphere is ob- 
servable. You notice none of those phenomena which in other 
climates depend on an excess of water in the air, and on sud- 
den changes of temperature. The moisture does not condense 
on your windows, nor on the plastered walls; salt does not 
liquify, nor even exhibit the slightest dampness ; and the house- 
