of air moving from about the 30th degree of
latitude towards the equator. The diurnal motion of the earth makes them
incline from the eastward, so that in the northern hemisphere they are
from the N.E., and in the southern hemisphere from the S.E. Their
geographical position in latitude varies with the declination of the
sun. In some parts of the world, as the Bay of Bengal and China Sea, the
action of the sun on the neighbouring land has the power of reversing
the trades; the winds are there called _monsoons_.

TRADING-VESSEL. _See_ TRADER.

TRAIL A PIKE, TO. To hold the spear end in the right hand, and the butt
trailed behind the bearer.

TRAIL-BOARDS. A carved board on each side of the stem, reaching from it
to the figure, or to the brackets. The carved work between the
cheek-knees of the head at the heel of the figure.

TRAIN OR TRAIL OF ARTILLERY. A certain number of pieces of ordnance,
completely mounted and fitted with appurtenances and retinue of
attendants, ready to follow in rear of an army, &c. (_See_ BATTERING
GUNS.) Also, the hinder part of a gun-carriage.--_Train_ also signifies
a line of gunpowder or other combustible material forming a
communication with any body intended to be set on fire or exploded.

TRAINING-LEVEL. A gravitating instrument for the same purpose as the
training-pendulum.

TRAINING-PENDULUM. An improved pendulum to facilitate the accurate
elevation and depression of guns on board ship, by means of coloured
spirits or quicksilver confined in a tube.

TRAINING-SHIP FOR THE MERCHANT SERVICE. A vessel properly equipped with
instructors and means to rear able-bodied lads for the merchant service.

TRAINING-SHIP FOR NAVAL CADETS. H.M.S. _Britannia_, commanded by a
captain and complement of officers for the primary training of naval
cadets. They are nominated by the first lord, examined as to ability and
constitution, and entered on trial. If they pass a pretty rigid
examination, they are nominated to ships; but if they fail, they are not
admitted into the navy. Great interest is required for a nomination.

TRAIN-TACKLE. A tackle which is during action hooked to an eye-bolt in
the train of a gun-carriage, and to a ring-bolt in the deck; its use is
to prevent the gun from running out of the port whilst loading, and for
running it in when fired.

TRAJECTORY. An astronomical term for the orbital curve described by a
planet or comet, now seldom used in that science, but generally emplo