. Even if the
friction retarded the great tidal wave uniformly, the high tide on the
days of full or change should always occur at fixed hours; but,
unfortunately, there is no such delightful theory of the tides as this
would imply. At Greenock no doubt there is high water at or about noon
on the day of full or change; and if it could be similarly said that
on the day of full or change there was high water everywhere at local
noon, then the equilibrium theory of the tides, as it is called,
would be beautifully simple. But this is not the case. Even around our
own coasts the discrepancies are such as to utterly discredit the
theory as offering any practical guide. At Aberdeen the high tide does
not appear till an hour later than the doctrine would suggest. It is
two hours late at London, three at Tynemouth, four at Tralee, five at
Sligo, and six at Hull. This last port would be indeed the haven of
refuge for those who believe that the low tide ought to be under the
moon. At Hull this is no doubt the case; and if at all other places
the water behaved as it does at Hull, why then, of course, it would
follow that the law of low water under the moon was generally true.
But then this would not tally with the condition of affairs at the
other places I have named; and to complete the cycle I shall add a few
more. At Bristol the high water does not get up until seven hours
after the moon has passed the meridian, at Arklow the delay is eight
hours, at Yarmouth it is nine, at the Needles it is ten hours, while
lastly, the moon has nearly got back to the meridian again ere it has
succeeded in dragging up the tide on which Liverpool's great commerce
so largely depends.

Nor does the result of studying the tides along other coasts beside
our own decide more conclusively on the mooted point. Even ports in
the vast ocean give a very uncertain response. Kerguelen Island and
Santa Cruz might seem to prove that the high tide occurs under the
moon, but unfortunately both Fiji and Ascension seem to present us
with an equally satisfactory demonstration, that beneath the moon is
the invariable home of low water.

I do not mean to say that the study of the tides is in other respects
such a confused subject as the facts I have stated would seem to
indicate. It becomes rather puzzling, no doubt, when we compare the
tides at one port with the tides elsewhere. The law and order are,
then, by no means conspicuous, they are often hardly discernibl