[December, 
768 Fog Lore. 
cultural drying machinery, for which he has received the 
gold medals of the Society of Arts and of the Highland an 
Agricultural Society of Scotland. He proposes to ereCt at 
the outfalls of the London sewerage systems at Barking an^ 
Crossness huge fans, to be set in motion by tidal power, and 
by their agency to cause an inrush of air into the sewers all 
over the metropolis, whilst fresh air would stieam in from 
the country on all sides. . 
It will be admitted that to ventilate the sewers in this 
manner by the entrance of the air of the streets rather than by 
the egress of sewage gas would, if otherwise practicable, be a 
decided advantage, not merely in times of fog, but all the 
year round. It is also, we believe, conceded that the rise 
and fall of the tide might be made to yield power equal to 
the work required. But there are certain difficulties of a 
most formidable nature. TLhe multitude of apertures by 
which air can penetrate into the sewers are so many that it 
becomes doubtful whether any conceivable exhaustion applied 
at Barking Creek would cause an in-draught into the sewers 
at Kensington, Pimlico, or Chelsea. It may also be asked 
whether the fog, if drawn out at the sewer mouths at Bark- 
ing or Crossness, would not be carried back to the metro- 
polis by the slight easterly current which generally prevails 
in foggy weather. We should very much like to see the 
experiment tried in some town of smaller extent than Lon- 
don where tidal power was available. It would be important 
to learn to what distance from the exhaustion-fans an in- 
rush of air into the sewers could be traced. 
There is another projeCt of a far more gigantic nature, 
which along with a number of other important objefts, would 
have a two-fold aCtion upon the fog difficulty. It has long 
been known that by boring to a sufficient depth water of a 
very high temperature can be obtained. The suggestion, 
therefore, lay very near that wherever a water supply suffi- 
cient in quantity and of a sufficient heat could be obtained 
entire towns might be warmed, as are now our conservatories 
by means of hot water pipes. Not only could dwelling houses 
thus be kept at a comfortable temperature all the year round 
without the combustion of fuel and the production of smoke, 
but the streets might in winter be so far heated that snow 
could not lie and that mud would be quickly dried up. This 
splendid project has, we understand, been to some extent 
reduced to practice in America. We should submit that a 
town thus warmed would be almost entirely free from fog, 
and that on three accounts. Ordinary fogs are phenomena 
connected with a very low temperature, and dissolve as the 
