194 THE FOG-MAP. 



ther obliterated. Hence if one takes post some- 

 where about Earl's -court, on a morning with the 

 wind at east, first comes the fog of Brompton, and 

 part of Chelsea and Knightsbridge ; then comes 

 the Green Park, a great deal lighter. St. James's 

 is not very dense, because the houses there are 

 large, and the fires not many. It then gradually 

 thickens to St. Giles's, and the hundreds of Drury. 

 Lincoln's Inn Fields lighten the prospect a little ; 

 but the thick mass of buildings all the way to St. 

 Paul's, make it soon dark again. St. Paul's is 

 but a speck ; and after that it is usually dark as 

 Erebus till you are quite tired of it. If the fog 

 of one of the great breweries, or other works, 

 which bountifully bestows all their smoke on the 

 neighbourhood, happens to pass over you, it is 

 perfect obscurity, more especially if the air which 

 is now passing over you happened to be there 

 when they were feeding the fire.. 



The London fog is no indication of rain, nor, 

 indeed, are any of the creeping fogs that are 

 formed in the hollows. They are, indeed, the 

 very reverse they show that the upper air resists 

 and keeps down the fog, so that the temperature 

 of its own humidity is not altered. But the Lon- 

 don fog has a rain of its own, and that rain is 

 filthy to man and pernicious to vegetation. It 

 rains soot and a " villanous combination" of acrid 

 matters, which soil the people and their provisions, 

 even while they are in the act of eating. Broc- 

 coli, and also the close-leaved vegetables, always 

 have a nauseous bitter taste in thick fogs. 



But the fog depends on the quantity of mois- 

 ture there is in the earth, or mud, or whatever 

 happens to be exposed to the air; and so the 



