— 
pela 
XI. On the Cause of Ebbing and Flowing Springs. By GaviN 
IN@xis, Esq. 
To Mr. Tilloch. 
Srp, — As you have again brought into notice the ebbing 
and flowing spring of pure fresh water in Bridlington harbour in 
the 227th Number of your valuable Magazine, I beg leave to 
send the substance of some obsetvations intended to have been 
submitted to you at the time Dr. Storer’s communication to Sir 
J. Banks was published i in your xlvth volume, page 432. 
Dr.S., after relating the circumstances which led tothe discovery 
of the spring, says: ‘¢As soon as the surface water in the harbour 
during the flowing of the tide has arrived at a level of 49 to 50 
inches lower than the top of the bore, the water begins to flow 
from it in a stream equal to its calibre; the impetus of which is 
increased as the tide advances, and may be observed to be pro- 
elled with much ferce after the bore is overflowed by the tide. 
The discharge continues from four to five hours, 7.e. till the tide in 
returning falls to the same ievel at which it began to flow.—The 
rule appears to be, that the column of spring water in the bore 
is always supported at a height of 49 to 50 inches above the level 
of the tide at any given time.”— Such is the state of facts,” 
continues the Doctor; “ and it appears to open a subject of 
curious investigation to those whose habits and practical know- 
ledge qualify them for it. The appearances seem, tot to ad- 
mit of any satisfactory explanation, without supposing some mode 
of subterranean communication, by which the water of the sea 
and that of the spring in question are brought into actual con- 
tact so as to exert a reciprocal action.” 
I beg leave to differ from the Doctor in supposing the rise of 
the fresh water above the level of the tide to proceed from these 
waters coming into actual contact, upon the principle of two 
liquids of different specific gravities in an inverted syphon. 
The facts themselves are at variance with this hypothesis. 
The well-known specific gravity of the German Ocean does 
not so far exceed that of pure spring water as to equal a column 
of 49 to 50 inches of superior altitude. The stratum of very 
solid clay, the tapping of which procured for Bridlington this 
wonderful supply of very fine water, will be found upon examina- 
tion to extend not only from Flamborough Head by the Smith- 
wick Sands to SpurnPoint, but to underlie Bridlington, the whole 
Wolds behind, and up the country till it runs out and is succeeded 
by that cretaceous gravelly soil whose dipping stratum occupies 
the intermediate space betwixt the clay and the rock. To this 
alone is to be attributed the want of water in the Wolds; the 
Vol. 50, No,232. August 1817, ¥ few 
