Fog

Sir Henry Maybury, considered the greatest expert on roads in the world, gave a few interesting side-lights on that yellow-back, thick, choking, aeriform known prosaically as " London fog":

" In the non-foggy month of June, 54 tons of dirt were deposited from the air on a square mile in the City of London.

" During the past three years there had been 27 days of ground fog; the number of buses unable to complete their scheduled journeys, 10,202; mileage lost, 434,457.

" In February, 1921, a dense fog, starting at 6 p. m., caused 1,436 buses to lose 33,266 miles, while 189 were taken off with a loss of 39,000 miles."

Nothing was said about the remaining traffic which is obliged to travel at a snail's pace, owing to the impenetrable density of the fog.

The fog is a soot-laden white mist of great weight. Owing to the warmth of the ground and the consequent lighter pressure the fog descends from its chilly couch in the skies--that is, when there is no wind to blow it away--and covers the earth until the heat gradually dissipates it. Were it not for the soot, the mist would probably be dissipated by the surface heat as it descended.