ing reminded of now and then. Poor Billy Towler was very powerfully
reminded of it on the day following his night-adventure with the ravens;
and his master was taught that the best-laid plans of men, as well as
mice, are apt to get disordered, as the sequel will show.

Next morning the look-out on board the Gull lightship reported the
Trinity steam-tender in sight, off the mouth of Ramsgate harbour, and
the ensign was at once hoisted as an intimation that she had been
observed.

This arrangement, by the way, of hoisting a signal on board the floating
lights when any of the Trinity yachts chance to heave in sight, is a
clever device, whereby the vigilance of light-ship crews is secured,
because the time of the appearing of these yachts is irregular, and,
therefore, a matter of uncertainty. Every one knows the natural and
almost irresistible tendency of the human mind to relax in vigilance
when the demand on attention is continual--that the act, by becoming a
mere matter of daily routine, loses much of its intensity. The crews of
floating lights are, more than most men, required to be perpetually on
the alert, because, besides the danger that would threaten innumerable
ships should their vessels drift from their stations, or any part of
their management be neglected, there is great danger to themselves of
being run into during dark stormy nights or foggy days. Constant
vigilance is partly secured, no doubt, by a sense of duty in the men; it
is increased by the feeling of personal risk that would result from
carelessness; and it is almost perfected by the order for the hoisting
of a flag as above referred to.

The superintendent of the district of which Ramsgate is head-quarters,
goes out regularly once every month in the tender to effect what is
styled "the relief,"--that is, to change the men, each of whom passes
two months aboard and one month on shore, while the masters and mates
alternately have a month on shore and a month on board. At the same
time he puts on board of the four vessels of which he has charge--
namely, the _Goodwin_, the _Gull_, the _South-sandhead_, and the _Varne_
light-ships,--water, coal, provisions, and oil for the month, and such
stores as may be required; returning with the men relieved and the empty
casks and cans, etcetera, to Ramsgate harbour. Besides this, the tender
is constantly obliged to go out at irregular intervals--it may be even
several times in a week--for the purpose of re