490 
THE GEOLOGIST, 
NOTES AND QUERIES. 
The Deposition of Wabp. — Dear Sir, — During a sliori visit in York- 
sliire, I have had my attention again dii-ccf-ed to tlic process of warping, and 
upon wliich I am anxious to submit two questions. 
1st. Where does tliis warp come from ? 
That it comes from the sea is certain, because it is only carried on to the low 
lands at high tides. The amount of sediment brought up these rivers, especially 
in. (In/ seanoiis, is very considerable. Upon one farm near Howden, I am told 
that a deposit of warp two feet thick has been formed by four spring-tides, 
which, with the intervals of neap-tides — when the land would not be flooded, 
would occupy about two months. 
In wet seasons, when it miglit be expected tliat a larger amount of solid 
matter would be carried into the rivers from the higher lands, the quantity of 
warp deposited is far below the average, and that the greatest deposits are in 
dry seasons. 
Tliis warp in the Humber and its tributaries seems to be exhaustless. It 
has been deposited on the lands sui'rounding these rivers for a number of years, 
and it is as abundant now as ever. 
The question then naturally arises, whence comes this warp ? Is it the dis- 
integrated materials from the rocks wliich form the abrupt coast of Yorkshire ? 
Throughout the whole extent of this coast the sea is constantly wearing away 
its clili's, corroding its promontories into fantastic forms, and hollowing its rocks 
into " deep and solemn caverns." At Withemsea, Hornsea, Bridlington, and 
many other places, there have been remarkable encroachments of the sea with- 
in a few years, to the destruction of some miles of surface-land. If this warp 
be the worn materials of these rocks, why do not other rivers, such as the Tees 
and the Tyne, deposit it on their surrounding lands ? 
This warp is procured on the low-lands adjoining the Humber, &c., as a sub- 
stitute for manure ; and the prolific crops both of cereal and roots which it 
produces is a suflicient proof of its fertilizing properties. The ordmary crops 
of wheat, for instance, average as much as six quarters to the acre, and the 
potatos in the London market grown on these warped lands are said to be 
preferred to any other. 
2nd. How is it that the Humber and its tributaries — the Trent, Ouse, Don, 
&c., are the only rivers in Great Britain that de]50sit " warp" ? 
That there is no other river in this country which deposits solid matter such 
as "warp," on the low lands that may be flooded by it at high tides I am 
creditably informed is a fuUy ascertained fact. I have had but one opportunity 
for inquiry of a friend residing near the Mersey, who tells me, if the waters of 
that river were allowed to overflow the adjacent lands at high tides, which is 
sometimes done for the hake of u-rigation, that no sediment whatever would be 
deposited ; any deposit hke the warp of the Yorkshire rivers would bury the 
grass to the depth of several inches, which the water was intended to invigorate. 
There is another fact or two which appears to me to have a geological bear- 
ing, and which I wiU state as briefly as possible. 
You wdl no doubt remember a period when the herring-fishery ofl' Boston, at 
what is called Boston Deep, was the most important and extensive herring- 
fishery in these islands. Great Yarmouth was also justly celebrated for its 
mackerel, and I believe it was the custom at one time to send to the reigning 
sovereign of England the first fish of tliis species that was caught in those seas. 
