Clement Reid — O^i Dust and Soils. 167 



westward.^ Probably, howevei", it would not travel far at the pre- 

 sent day, were it not for the plough destroying the vegetation which 

 would otherwise stop it. This travelling of the sand is well known, 

 but curiously it seems often to be overlooked that the same wind that 

 moves the sand must necessarily raise clouds of dust, which from its 

 lightness would rise in lai'ger quantities, travel further, and be 

 dispersed widely over hill and dale.^ 



It is not uncommon on these Wolds, and still more on the light 

 soils of the Norfolk coast, for the whole of the finer portion of the 

 soil, and the seed, to be blown away by the equinoctial gales. A 

 few years ago a field near Cromer was sown three times in succes- 

 sion in one spring, and finally was left fallow, as the whole of the 

 soil was banked like a snow-drift against the hedge. ^ 



The dust that annoys us so much in March, and hurts one's eyes, 

 is coarse and gritty, the finer dust that is constantly moving is 

 noticed, and troubles us no more, than the more purely carbonaceous 

 and organic dust of towns. That the air is full of dust is a well- 

 known fact : every one has probably noticed the dust-haze which 

 obscures the view after a long spell of dry weather, to disappear 

 directly the dust is washed down by a shower. Dust, to some 

 extent, however, meteoric, occurs even on the snow, and the recent 

 eruption of Krakatoa proves to what a distance the finer particles 

 may be carried. Ordinary dust from our fields will travel, when 

 once it has been raised, as far and as easily as that of a volcano. 

 If instead of a Chalk Wold, we examine the flat top of a church 

 tower, we often find in each sheltered corner of the leads a small 

 heap of dust in which plants have taken root. Lately I observed 

 this dust on the leaded tower of Immingham Church, a church 

 standing in the middle of a wet marshy country, and therefore, one 

 would think, even less likely to receive dust than most. Recent 

 British dust deposits are so largely due to the agency of man in 

 laying bare the soil, that it is doubtful how far we can appeal 

 to them as evidence of the former movement of the dust. Still, as 

 I attempt to show below, with a colder climate the destruction of 

 the vegetation to a large extent takes place naturally ; thus, perhaps, 

 the present deposition of dust is below, not above, the ancient 

 amount. 



Perhaps a mistake is made in considering that the dust blows most 

 in hot summer weather. If my own observations, made during the 

 last nine years, can be trusted, dust rises most during the winter, 

 when the vegetation has died down, and especially with the dry east 

 winds of March. An unexpected instance of this was observed in 

 the North Yorkshire Moors during the winter of 1879-80. Great 

 part of these Moors are quite uncultivated, and rise to about a 

 thousand feet above the sea. Here and there are patches of shale 



^ There is very little sandy land in other directions. 



2 See however Proctor, " Pleasant Ways in Science," p. ?>79 ; von Richthofen, 

 "China," vol. i. ; and von Richthofen, "On the Mode of Origin of the Loess," 

 Geol. Mag. Dec. II. Vol. IX. p. 293. 



■* See also Johnston and Cameron, op. cit. p. 191. 



