84
CHELMSFORD WATER SUPPLY.
many years to come, though its purity can never be quite above sus-
picion. But the alternative of sinking through the London Clay to
the Chalk would have been so much more expensive that it is not to
be wondered at that an already available supply from the Glacial
gravel has been preferred.
Close to the water-tower there is a large pit in which the Glacial
gravel and the Boulder Clay may both be seen, their line of junc-
tion being a very irregular one.
Food of the Otter.—(See Essex Naturalist, ii., 272.) In an interesting
paper on "Water Poachers," by Mr, John Watson, in the "Nineteenth Century,"
for October, 1889 (pp. 695-709), we have the following very necessary defence of
the rapidly disappearing Otter : "The creature against which the angler 'breathes
hot roarings out' is the Otter. But how few fish does the Otter really destroy !
The evidence to be gathered by those who live along its streams all goes to
show that Eels and Fresh-water Crayfish form the staple of its food. It wanders
miles in a night in search of these, and will not partake of soft-bodied fish so
long as they can be found. The economy of the Otter ought certainly not to be
overlooked in connection with sport and our fish supply. Probably its increas-
ing rarity has much to do with the disease alluded to, as had the extermination
of the nobler birds of prey with the Grouse disease. A Falcon always takes
the easiest chance at its prey, and an Otter captures the slowest fish. In each case
they kill off the weakest, the most diseased, and thereby secure the survival
of the fittest. Most of the newspaper paragraphs anent the doings of Otters are
mere legendary stories without foundation in fact. The Otter is not a 'fish-
slicer.' Salmon found upon the rocks with the flesh bitten from the shoulders
are oftener than not there by agents other than Lutra. A great deal of
unnatural history has been written concerning the 'water-dog,' mostly by those
who have never had opportunity of studying the Otter in its haunts. That it
occasionally destroys fish we do not deny ; but this liking has become such a
stereotyped fact (?) in Natural History that it is glibly repeated, parrot-like, and
has continued so long that most have come to accept it. Ask the Otter-
hunter, the old angler of the northern streams, the field naturalist who has many
a night stretched his length along a slab of rock to observe the Otter at home—
each has the same answer. Abundance of Otters and plenty of Trout exist side by
side; and where the fastnesses of the former are impregnable, there disease is
foreign to the streams. Many Otters, many Trout ; this is a bit of Nature's
economy which there is no gainsaying. Here is an actual incident. There is a
certain reach of a well-known trout-stream which is so overgrown with wood and
coppice as to render it unfishable. This reach swarms with handsome, well-fed
Trout; and yet, far back among the rocky shelves of the river, a brood of Otters
are brought forth annually—have been, in fact, time out of mind. And yet
another incident. Of forty-five dead Otters killed by hunting, in two only
were there any remains of fish-food, and this consisted of Eels—deadly enemies
either to Trout-stream or Salmon-river. These forty-five Otters for the most part
were killed before six in the morning, and consequently when their stomachs
were most likely to contain traces of what had been taken in the night's
fishing."