THE BREAKING OF THE SHROPSHIRE MERES. 
57 
Shropshire, providing that no part of the rim of this old basin were 
worn away, and swamp Shrewsbury and Oswestry beneath its 
waves. Thousands of acres have been recovered by artificial 
drainage within historic times, and the discovery of prehistoric 
dwelling-places once surrounded by water, and ancient canoes in 
land now dry, point to a condition of things very different from 
what we see at the present time. There yet remain the wide, wet 
moorlands of Whixall Moss, stretching out of this county into 
Flintshire, in many parts dangerous to traverse, or altogether 
impassable ; and Cole Mere, White Mere, Ellesmere, Newton Mere, 
and many others of smaller dimensions, to confirm the geological 
theory. In some of these meres a phenomenon has been long 
observed, and much discussed, but not satisfactorily explained till 
within the last ten years. It is true that the materials for an 
explanation have existed for a much longer period, but were not 
utilised till one of the Natural History Societies of the Midland 
Union, the Caradoc Field Club, appointed a commission of inquiry, 
consisting of three of its members, to investigate the subject. The 
result of that investigation I will endeavour to communicate in a few 
words. The phenomenon consists in the periodical appearance of a 
turbid condition of the water of certain meres, arising apparently 
from some material of a green or yellowish-green matter floating in 
it, or collecting as a scum upon its surface, and usually, after a 
time, emitting a putrid odour. When in this state the water is 
altogether unfit for domestic purposes, and the effect upon the fishes 
is so pernicious that they become disinclined to take the bait, and 
fishing has to be abandoned. The inconvenience suffered by those 
who draw their water from meres, subject to this nuisance, is very 
great, and filtering is rendered ineffective owing to the green 
matter filling up the filtering beds. The usual time of its appear¬ 
ance is in the autumn, but it occasionally occurs in the early spring, 
and lasts from a few days to a month. But while it is actually in 
the process it will suddenly disappear for a day, reappearing again 
the next day, or it may exist on one side of the mere—the lee side— 
while nothing is to be seen on the opposite shore. There is 
one of the meres near Ellesmere—Blackmere—which has the 
March, 1893. 
