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to Padstow. These sands have a large percentage of crushed and broken shells, 
mingled with other materials, consequently thousands of cart loads are annually 
carried away from the coast by the farmers to spread on their land, the lime from 
the shells adding fertility to the soil on which it is spread. 
Houses are sometimes buried beneath the accumulations of the blown or drifted 
sand, and at some future period, owing to the sand shifting, again re-appear. 
Gwithian and Phillack are partially buried in sand. One accumulation on the 
barton of Upton, is said to have occurred nearly a century since, and so sudden 
was the irruption of sand that a large farm was overwhelmed in a moment, and 
the farmer and his family were obliged to get through the upper chamber window 
to effect their escape. In 1808 the sand shifting, disclosed the farm-house after 
being buried for nearly a century. Two fields are now covered to a depth of 
twelve feet, which a few years since were quite clear. 
Sir Henry De la Beche considered the Towans of Cornwall as composed of two 
parts of different ages. These two portions must have been separated by a period 
of considerable duration, as vegetable mould and other indications of the cessation 
of sandy deposits are apparent. Probably after the first period of accumulation, 
the land became elevated above the reach of sand drifts, and afterwards again 
became subject to their influence. 
The progress of the sand as it emerges from the sea is as follows : — After a 
storm or very high tide, a large quantity is frequently driven upon the shore, when 
this becomes dry and the wind blows strongly landward, the advance of the sand 
in minute undulations or tiny waves is clearly perceptible, and if not arrested in 
time it rolls over the fertile lands, until it completely covers the superficial surface 
soil. In time the lower portions of the sand become indurated into sandstones. 
The Towans or Sand-hills are supposed by some to arise from other causes, no 
longer in operation, but the progress of the sand is now so well understood that 
no doubt can exist on the subject among scientific men. 
The most effectual method of arresting the gradual advance of the sand is to 
form a barrier by sowing the seed, or planting those species of plants that thrive 
in sandy waters, and whose long creeping roots ramify in every direction beneath 
the surface, forming a net-work which checks the rapid progress of the sand, 
causing it to form mounds around the plants, and eventually a barrier is raised 
which for a time saves the adjacent district from further encroachment. 
The plants which are best suitable for arresting the inroads of sand are 
Ammophila arenaria (sea reed), Triticum junceum (sea wheat grass), Hippophce 
rhamnoides (sand thorn), Cakile maritima (sea rocket), Salsola kali (saltwort), 
Sonchus (sand thistle), and some others. 
Wheresoever these plants grow the effect is soon visible, a few of them will 
arrest portions of sand and collect it into small hillocks, these hillocks, as vegeta- 
tion progresses, are formed into larger ones, till by degrees a mound of consider- 
able size is formed, and which the matted roots of the plants keep from dispersion. 
In proof of the influence vegetation exercises over arid wastes, it is recorded that 
