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The huge balloon was 43 feet in diameter and 176 feet long； with a gas
capacity of 235；000 cubic feet。 To maintain the external form of the
envelope a smaller balloon； or compensator； was placed inside the larger
one。 The framework was of bamboo； and the car was attached by about
eighty wire…cables。 The wooden deck was about 123 feet in length。 Two
50…horse…power engines drove four propellers； two of which were at either
end。
The inventor employed a most ingenious contrivance to preserve the
horizontal balance of the air…ship。 Fitted； one at each end of the carriage；
were two 50…gallon tanks。 These tanks were connected with a long pipe； in
the centre of which was a hand…pump。 When the bow of the air…ship
dipped； the man at the pump could transfer some of the water from the
fore…tank to the after…tank； and the ship would right itself。 The water could
similarly be transferred from the after…tank to the fore…tank when the stern
of the craft pointed downwards。
There were many reports； in the early months of 1905； that the air…ship
was going to be brought out from the shed for its trial flights； and the
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writer； in common with many other residents in the vicinity of the park；
made dozens of journeys to the shed in the expectation of seeing the
mighty dirigible sail away。 But for months we were doomed to
disappointment； something always seemed to go wrong at the last minute；
and the flight had to be postponed。
At last； in 1905； the first ascent took place。 It was unsuccessful。 The
huge balloon； made of tussore silk； cruised about for some time； then
drifted away with the breeze； and came to grief in landing。
A clever inventor of air…ships； a young Welshman； Mr。 E。 T。 Willows；
designed in 1910； an air…ship in which he flew from Cardiff to London in
the darka distance of 139 miles。 In the same craft he crossed the English
Channel a little later。
Mr。 Willows has a large shed in the London aerodrome at Hendon； and
he is at present working there on a new air…ship。 For some time he has
been the only successful private builder of air…ships in Great Britain。 The
Navy possess a small Willows air…ship。
Messrs。 Vickers； the famous builders of battleships； are giving
attention to the construction of air…ships for the Navy； in their works at
Walney Island； Barrow…in…Furness。 This firm has erected an enormous
shed； 540 feet long； 150 feet broad； and 98 feet high。 In this shed two of
the largest air…ships can be built side by side。 Close at hand is an extensive
factory for the production of hydrogen gas。
At each end of the roof are towers from which the difficult task of
safely removing an air…ship from the shed can be directed。
At the time of writing； the redoubtable DORA （Defence of the Realm
Act） forbids any but the vaguest references to what is going forward in the
way of additions to our air forces。 But it may be stated that air…ships are
included in the great constructive programme now being carried out。 It is
not long since the citizens of Glasgow were treated to the spectacle of a
full…sized British 〃Zep〃 circling round the city prior to her journey south；
and so to regions unspecified。 And use； too； is being found by the naval
arm for that curious hybrid the 〃Blimp〃； which may be described as a
cross between an aeroplane and an air…ship。
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CHAPTER VIII The First Attempts to Steer a
Balloon
For nearly a century after the invention of the Montgolfier and
Charlier balloons there was not much progress made in the science of
aeronautics。 True； inventors such as Charles Green suggested and carried
out new methods of inflating balloons； and scientific observations of great
importance were made by balloonists both in Britain and on the Continent。
But in the all…important work of steering the huge craft； progress was for
many years practically at a standstill。 All that the balloonist could do in
controlling his balloon was to make it ascend or descend at will； he could
not guide its direction of flight。 No doubt pioneers of aeronautics early
turned their attention to the problem of providing some apparatus； or some
method； of steering their craft。 One inventor suggested the hoisting of a
huge sail at the side of the envelope； but when this was done the balloon
simply turned round with the sail to the front。 It had no effect on the
direction of flight of the balloon。 〃Would not a rudder be of use？〃
someone asked。 This plan was also tried； but was equally unsuccessful。
Perhaps some of us may wonder how it is that a rudder is not as
serviceable on a balloon as it is on the stern of a boat。 Have you ever
found yourself in a boat on a calm day； drifting idly down stream； and
going just as fast as the stream goes？ Work the rudder how you may； you
will not alter the boat's course。 But supposing your boat moves faster than
the stream； or by some means or other is made to travel slower than the
current； then your rudder will act； and you may take what direction you
will。
It was soon seen that if some method could be adopted whereby the
balloon moved through the air faster or slower than the wind； then the
aeronaut would be able to steer it。 Nowadays a balloon's pace can be
accelerated by means of a powerful motor…engine； but the invention of the
petrol…engine is very recent。 Indeed； the cause of the long delay in the
construction of a steerable balloon was that a suitable engine could not be
found。 A steam…engine； with a boiler of sufficient power to propel a
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balloon； is so heavy that it would require a balloon of impossible size to
lift it。
One of the first serious attempts to steer a balloon by means of engine
power was that made by M。 Giffard in 1852。 Giffard's balloon was about
100 feet long and 40 feet in diameter； and resembled