to the security of our out-lying dominions.

We have now reached a point where it is incumbent on us to face certain
difficulties which beset the airship of large dimensions, and which are
always magnified by its detractors. Firstly, there is the expense of
sheds in which to house it; secondly, the large number of trained
personnel to assist in landing and handling it when on the ground;
thirdly, the risks attendant on the weather--for the airship is still
considered the general public as a fair-weather craft; and fourthly,
though this is principally in connection with its efficiency for
military purposes, its vulnerability. We will deal with the four
difficulties enumerated under these headings seriatim, and endeavour to
show to what extent they may be surmounted if not entirely removed.

The solution of the first two problems may be summed up in two words:
"mooring out"; on the success of this it is considered that the whole
future of airships for commercial purposes rests. It will be essential
that in every country which the airship visits on its voyages, one
large central station is established for housing and repairs. The
position of such a station is dependent on good weather conditions and
the best railway facilities possible. In all respects this station
will be comparable to a dry dock for surface vessels. The airship will
be taken into the shed for overhaul of hull structure, renewing of
gasbags or outer cover, and in short to undergo a periodical refit.
The cost of a shed capable of housing two rigid airships, even at the
present time, should not greatly exceed L500,000. This sum, though
considerable, is but a small item compared with the cost of
constructing docks to accommodate the Atlantic liner, and when once
completed the cost of maintenance is small when weighed against the
amount annually expended in dredging and making good the wear and tear
of a dock.

Apart from these occasional visits to a shed, the airship, in the
ordinary way at the end of a voyage, will pick up its moorings as does
the big steamer, and land its passengers and cargo, at the same time
replenishing its supplies of fuel, gas, provisions, etc., while minor
repairs to the machinery can be carried out as she rides in the air.

A completely satisfactory solution of the mooring problem for the rigid
airship has yet to reach its consummation. We saw in the previous
chapter how, in the case of small non-rigids, they were sheltered