THE Mariner's Compass consists of a circular card, the circumference of which is divided into 32 equal parts, called points; these are again divided into half-points and quarter-points, and finally into 360 equal parts, called degrees.

The essential part of a compass is a magnetized needle, which (allowing for what is called "variation") always points towards the North Pole. Upon this needle the card as described above is laid and attached, the former being in turn balanced upon a hard pivot working in chrysolite or agate. The whole is enclosed in a brass bowl or box, and fitted with a glass cover.

When it is used as a Steering Compass the inside of the bowl has a vertical black line painted upon it, which is known as the "Lubber Line," and which is in direct alignment with the ship's head.

Compasses vary much in size, from 7½ inches to 15 inches in diameter.

A Pole or Masthead Compass is so called from the fact that it is mounted as far away as possible from the iron hull or body of the ship in order to be removed from the magnetic influence of the latter.

The Standard Compass is the compass by which the ship is navigated. It is generally of the Pole Compass type.

Ship Logs are of various types, those commonly in use at the present day being known as Patent Logs. They have an adjustable rotator or screw, and a registering dial which records the distance covered.

Their object is to indicate the speed of the ship by recording the distance covered in a given time.

On the rotator are fixed four or five blades, resembling the blades of a screw propeller. These blades, when the machine is towed astern, cause revolutions which are recorded on the dial face which is affixed to the taffrail, and indicate the distance run to great exactness.

To "box the Compass" is to give, in consecutive rotation from east to West, the various divisions and sub-divisions indicated on the card of the Compass as follows: —

At noon, if you hold your watch horizontally, with the hour hand pointing to the sun, the hands will direct you to the South, the figure VI. to the North, the figure IX. to the East, and the figure III. to the West.

Before or after noon, if you point the hour hand to the sun, the South will be indicated by a point midway between the centre of the figure XII. and the hour hand.

If it be a.m., the figure XI. will point to the South; if it be p.m., the figure III. will point to the South; and so on. If you had a 24-hour dial, the figure XII. would always point to the South and the hour hand to the sun. Your watch must be correct and pointed to the sun's centre, and the compass will be true.

The "tracks" of the Atlantic Liners vary in length according to the seasons of the year. The eastward course is generally longer than the westward course, though both vary Within certain limits, and hence the time occupied by any ship on a particular passage is not to be necessarily taken as a test of speed.

The following routes, agreed to by the principal Steamship Companies, came into force January 15, 1899: —

Steer from Fastnet, or Bishop Rock, on Great Circle course, but nothing South, to cross the meridian of 47° West in Latitude 42° North, thence by either rhumb line, or Great Circle (or even North of the Great Circle, if an easterly current is encountered), to a position South of Nantucket Light-Vessel, thence to Fire Island Light-Vessel, when bound for New York, or to Five Fathom Bank South Light-Vessel, when bound for Philadelphia.

Steer from Fastnet, or Bishop Rock, on Great Circle course, but nothing South, to cross the meridian of 49° West in Latitude 46° North, thence by rhumb line, to cross the meridian of 60° West in Latitude 43° North, thence also by rhumb line, to a position South of Nantucket Light-Vessel, thence to Fire Island Light-Vessel, when bound to New York, or Five Fathom Bank South Light-Vessel when bound for Philadelphia.

At all seasons of the year steer a course from Sandy Hook Light-Vessel, or Five Fathom Bank South Light-Vessel, to cross the meridian of 70° West, nothing to the northward of Latitude 40° 10'.

Steer from 40° 10' North, and 70° West, by rhumb line, to cross the meridian of 47° West in Latitude 41° North, and from this last position nothing North of the Great Circle to Fastnet, when bound to the Irish Channel, or nothing North of the Great Circle to Bishop Rock, when bound to the English Channel.

Steer from Latitude 40° 10' North and Longitude 70° West, to cross the meridian of 60° West in Latitude 42° 0' North, thence by rhumb line to cross the meridian of 45° West in Latitude 46° 30' North, and from this last position nothing North of the Great Circle to Fastnet, when bound to the Irish Channel, and as near as possible to, but nothing North of; the Great Circle to Bishop Rock, always keeping South of the Latitude of Bishop Rock, when bound for the English Channel.