in
berths cut into woods or belts of trees, but for the rigid airship
something more secure and less at the mercy of the elements is required.

At the present moment three systems of mooring are in an experimental
stage: one, known as "the single-wire system," is now practically
acknowledged to fall short of perfection; the second, "the three-wire
system," and the third, "mooring to a mast," both have their champions,
but it is probable that the last will be the one finally chosen, and
when thoroughly tried out with its imperfections eliminated will
satisfy the most exacting critics.

The single-wire system is at the same time the simplest and most
obvious method which suggests itself, and means that the ship is
secured by a wire cable attached to a suitable point in the ship and
led to some fixed point on the ground. It has been found that an
airship secured in this way requires constant attention, and that
steering is always necessary to render her steady in the air.
Considerable improvement is obtained if a dragging weight is added to
the wire, as it tends to check to a considerable extent lateral motion
of the bow of the ship.

The three-wire system is an adaptation and an improvement on the one
previously mentioned. In this case the mooring point of the ship is
attached to three long wire cables, which, when raised in the air, form
a pyramid to the head of which the ship is attached. These wires are
led to bollards which form in plan an equilateral triangle. The lift
of the ship raises these wires off the ground, and if the ship is
trimmed up by the bows she will be found to resist the action of the
wind. A rigid airship moored out by this method remained in the open
for a considerable time and rendered the future of this experiment most
hopeful. It was resolved to continue these experiments by adding a
subsidiary system of wires with running blocks, the whole wiring to
form a polygon revolving round a fixed centre. The disadvantages of
this method appear to be rather serious. It seems that great
difficulty will always be found in picking up these moorings in a high
wind, and though this also applies to the method with the mast, the
initial obstacles do not appear to be so great. A powerful engine
driving a winch will be necessary to raise these heavy wires from the
ground, although of course the lift of the airship will assist in this.
Secondly, the lowering of passengers and cargo will not be easy as