on the sun.
It takes about an hour to make the calculations. The passengers on board
the ship during this interval are generally full of interest and
curiosity to know the result. They come out from their lunch at half
past twelve, and then they wait the remaining half hour with great
impatience. They are eager to know how far they have advanced on their
voyage since noon of the day before.

In order to let the passengers know the result, when it is determined,
the captain puts up a written notice, thus:--

Latitude, 44 deg. 26'.
Longitude, 16 deg. 31'.
Distance, 270.

The passengers, on seeing this notice, which is called a _bulletin_,
know at once, from the first two items, whereabouts on the ocean they
are; and from the last they learn that the distance which the ship has
come since the day before is 270 miles.

This plan of finding out the ship's place every day, and of ascertaining
the distance which she has sailed since the day before, would be
perfectly successful, and amply sufficient for all the purposes
required, if the sun could always be seen when the hour arrived for
making the observation; but this is not the fact. The sky is often
obscured by clouds for many days in succession; and, in fact, it
sometimes happens that the captain has scarcely an opportunity to get a
good observation during the whole voyage. There is, therefore, another
way by which the navigator can determine where the ship is, and how fast
she gets along on her voyage.

This second method consists of actually measuring the progress of the
ship through the water, by an instrument called the log and line. The
log--which, however, is not any log at all, but only a small piece of
board, loaded at one edge so as to float upright in the water--has a
long line attached to it, which line is wound upon a light windlass
called a reel. The line, except a small portion of it at the beginning
is marked off into lengths by small knots made in it at regular
intervals. There are little rags of different forms and colors tied into
these knots, so that they may easily be seen, and may also be
distinguished one from the other.

When the time comes for performing the operation of _heaving the log_,
as they call it, the men appointed for the purpose bring the log and the
reel to the stern of the ship. One man holds the log, and another man
the reel. There are two handles, one at each end of the reel, by which
the man who serves it can hold it up ove