riod that, according to Mr. Coxwell, Lord Wolseley made
ascents at home in a war balloon to form his own personal opinion of
their capabilities, and, expressing this opinion to one of his staff,
said that had he been able to employ balloons in the earlier stages of
the Soudan campaign the affair would not have lasted as many months as
it did years. This statement, however, should be read in conjunction
with another of the same officer in the "Soldier's Pocket Book,"
that "in a windy country balloons are useless." In the Boer War the
usefulness of the balloon was frequently tested, more particularly
during the siege of Ladysmith, when it was deemed of great value in
directing the fire of the British artillery, and again in Buller's
advance, where the balloon is credited with having located a
"death-trap" of the enemy at Spion Kop. Other all-important service was
rendered at Magersfontein. The Service balloon principally used was made
of goldbeaters' skin, containing about 10,000 cubic feet of hydrogen,
which had been produced by the action of sulphuric acid on zinc, and
compressed in steel cylinders. A special gas factory was, for the
purpose of the campaign, established at Cape Town.

It is here that reference must be made to some of the special work
undertaken by Mr. Eric S. Bruce, which dealt with the management of
captive balloons under different conditions, and with a system
of signalling thus rendered feasible. Mr. Bruce, who, since Major
Baden-Powell's retirement from the office, has devoted his best energies
as secretary to the advancement of the British Aeronautical Society,
was the inventor of the system of electric balloon signalling which
he supplied to the British Government, as well as to the Belgian and
Italian Governments. This system requires but a very small balloon, made
of three or four thicknesses of goldbeaters' skin, measuring from 7 to
10 feet in diameter, and needing only two or three gas cylinders for
inflation. Within the balloon, which is sufficiently translucent, are
placed several incandescent lamps in metallic circuit, with a source
of electricity on the ground. This source of electricity may consist of
batteries of moderate size or a portable hand dynamo. In the circuit
is placed an apparatus for making and breaking contact rapidly, and by
varying the duration of the flashes in the balloon telegraphic messages
may be easily transmitted. To overcome the difficulty of unsteadiness,
under cir