essentially to the employ ment of captive balloons in war, and in
1880 a company of the Royal Engineers was detailed to the care of
this work in the field. Six years previously the French military
department had adopted the captive balloon under Colonel
Laussedat, who was assisted among others by the well-known
Captain Renard. Germany was somewhat later in the field; the
military value of captive balloons was not appreciated and taken
into serious consideration here until 1884. But although British
efforts were preceded by the French the latter did not develop
the idea upon accepted military lines.

The British authorities were confronted with many searching
problems. One of the earliest and greatest difficulties
encountered was in connection with the gas for inflation. Coal
gas was not always readily available, so that hydrogen had to be
depended upon for the most part. But then another difficulty
arose. This was the manufacture of the requisite gas. Various
methods were tested, such as the electrolytic decomposition of
water, the decomposition of sulphuric acid by means of iron, the
reaction between slaked lime and zinc, and so forth.

But the drawbacks to every process, especially upon the field of
battle, when operations have to be conducted under extreme
difficulties and at high pressure, were speedily recognised.
While other nations concentrated their energies upon the
simplification of hydrogen-manufacturing apparatus for use upon
the battle-field, Great Britain abandoned all such processes in
toto. Our military organisation preferred to carry out the
production of the necessary gas at a convenient manufacturing
centre and to transport it, stored in steel cylinders under