the mastery of the air(操纵空气)-第20章
按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
experience； are able to turn out aeroplane engines as reliable； efficient； and
as light in pounds weight per horse…power as any aero engine in existence。
In the early days of aviation larger and better engines of British make
specially suited for aeroplanes were our most urgent need。
The story of the invention of the 〃Green〃 engine is a record of triumph
over great difficulties。
Early in 1909the memorable year when M。 Bleriot was firing the
enthusiasm of most engineers by his cross…Channel flight； when records
were being established at Rheims； and when M。 Paulhan won the great
prize of L10；000 for the London to Manchester flight Mr。 Green
conceived a number of ingenious ideas for an aero engine。
One of Mr。 Green's requirements was that the cylinders should be
made of cast…steel； and that they should come from a British foundry。 The
company that took the work in hand； the Aster Company； had confidence
in the inventor's ideas。 It is said that they had to waste 250 castings before
six perfect cylinders were produced。 It is estimated that the first Green
engine cost L6000。 These engines can be purchased for less than L500。
The closing months of 1909 saw the Green engine firmly established。
In October of that year Mr。 Moore Brabazon won the first all…British
competition of L1000 offered by the Daily Mail for the first machine to fly
a circular mile course。 His aeroplane was fitted with a 60…horse…power
Green aero engine。 In the same year M。 Michelin offered L1000 for a
long…distance flight in all…British aviation； this prize was also won by Mr。
Brabazon； who made a flight of 17 miles。
Some of Colonel Cody's achievements in aviation were made with the
Green engine。 In 1910 he succeeded in winning both the duration and
72
… Page 73…
THE MASTERY OF THE AIR
cross…country Michelin competitions； and in 1911 he again accomplished
similar feats。 In this year he also finished fourth in the all…round…Britain
race。 This was a most meritorious performance when it is remembered that
his Cathedral weighed nearly a ton and ahalf； and that the 60…horse…power
Green was practically 〃untouched〃； to use an engineering expression；
during the whole of the 1010…mile flight。
The following year saw Cody winning another Michelin prize for a
cross…country competition。 Here he made a flight of over 200 miles； and
his high opinion of the engine may be best described in the letter he wrote
to the company； saying： 〃If you kept the engine supplied from without
with petrol and oil； what was within would carry you through〃。
But the pinnacle of Mr。 Green's fame as an inventor was reached in
1913； when Mr。 Harry Hawker made his memorable waterplane flight
from Cowes to Lough Shinny； an account of which appears in a later
chapter。 His machine was fitted with a 100…horse…power Green； and with it
he flew 1043 miles of the 1540…miles course。
Though the complete course was not covered； neither Mr。 Sopwith
who built the machine and bore the expenses of the flightnor Mr。
Hawker attached any blame to the engine。 At a dinner of the Aero Club；
given in 1914； Mr。 Sopwith was most enthusiastic in discussing the merits
of the 〃Green〃； and after Harry Hawker had recovered from the effects of
his fall in Lough Shinny he remarked in reference to the engine： 〃It is the
best I have ever met。 I do not know any other that would have done
anything like the work。〃
At the same time that this race was being held the French had a
competition from Paris to Deauville； a distance of about 160 miles。 When
compared with the time and distance covered by Mr。 Hawker； the results
achieved by the French pilots； flying machines fitted with French engines；
were quite insignificant； thus proving how the British industry had caught
up； and even passed； its closest rivals。
In 1913 Mr。 Grahame White； with one of the 100…horse…power
〃Greens〃 succeeded in winning the duration Michelin with a flight of over
300 miles； carrying a mechanic and pilot； 85 gallons of petrol； and 12
gallons of lubricating oil。 Compulsory landings were made every 63 miles；
73
… Page 74…
THE MASTERY OF THE AIR
and the engine was stopped。 In spite of these trying conditions； the engine
ran； from start to finish； nearly nine hours without the slightest trouble。
Sufficient has been said to prove conclusively that the thought and
labour expended in the perfecting of the Green engine have not been
fruitless。
74
… Page 75…
THE MASTERY OF THE AIR
CHAPTER XXIV The Wright Biplane （Camber of
Planes）
Now that the internal…combustion engine had arrived； the Wrights at
once commenced the construction of an aeroplane which could be driven
by mechanical power。 Hitherto； as we have seen； they had made numerous
tests with motorless gliders； but though these tests gave them much
valuable information concerning the best methods of keeping their craft on
an even keel while in the air； they could never hope to make much
progress in practical flight until they adopted motor power which would
propel the machine through the air。
We may assume that the two brothers had closely studied the engines
patented by Daimler and Levassor； and； being of a mechanical turn of
mind themselves； they were able to build their own motor； with which
they could make experiments in power…driven flight。
Before we study the gradual progress of these experiments it would be
well to describe the Wright biplane。 The illustration facing p。 96 shows a
typical biplane； and though there are certain modifications in most modern
machines； the principles upon which it was built apply to all aeroplanes。
The two main supporting planes； A； B； are made of canvas stretched
tightly across a light frame； and are slightly curved； or arched； from front
to back。 This curve is technically known as the CAMBER； and upon the
camber depend the strength and speed of the machine。
If you turn back to Chapter XVII you will see that the plane is
modelled after the wing of a bird。 It has been found that the lifting power
of a plane gradually dwindles from the front edge or ENTERING EDGE；
as it is calledbackwards。 For this reason it is necessary to equip a
machine with a very long； narrow plane； rather than with a comparatively
broad but short plane。
Perhaps a little example will make this clear。 Suppose we had two
machines； one of which was fitted with planes 144 feet long and 1 foot
wide； and the other with planes 12 feet square。 In the former the entering
edge of the plane would be twelve times as great as in the latter； and the
75
… Page 76…
THE MASTERY OF THE AIR
lifting power would necessarily be much greater。 Thus； though both
machines have planes of the same area； each
