strong.  Some idea of the labour involved in its construction may
be gathered from the fact that this small and
insignificant-looking instrument, fitted in its aluminium case,
costs over L8.

CHAPTER XLII
How an Airman finds his Way

In the early days of aviation we frequently heard of an aviator
losing his way, and being compelled to descend some miles from
his required destination.  There are on record various instances
where airmen have lost their way when flying over the sea, and
have drifted so far from land that they have been drowned.  One
of the most notable of such disasters was that which occurred to
Mr. Hamel in 1914, when he was trying to cross the English
Channel.  It is presumed that this unfortunate pilot lost his
bearings in a fog, and that an, accident to his machine, or
a shortage of petrol, caused him to fall in the sea.

There are several reasons why air pilots go out of their course,
even though they are supplied with most efficient compasses.  One
cause of misdirection is the prevalence of a strong side wind. 
Suppose, for example, an airman intended to fly from Harwich to
Amsterdam.  A glance at the map will show that the latter place
is almost due east of Harwich.  We will assume that when the
pilot leaves Earth at Harwich the wind is blowing to the east;
that is, behind his back.

Now, however strong a wind may be, and in whatever direction it
blows, it always appears to be blowing full in a pilot's face.
Of course this is due to the fact that the rush of the machine
through the air "makes a wind", as we say.  Much the same sort of
thing is experienced on a bicycle; when out cycling we very
generally seem to have a "head" wind.

Suppose during his journey a very strong side wind sprang,up over
the North Sea.  The pilot would still keep steering his craft due
east, and it must be remembered that when well out at sea there
would be no familiar landmarks to guide him, so that he would
have to rely solely on his compass.  It is highly probable that
he would not feel the change of wind at all, but it is even more
probable that when land was ultimately reached he would be dozens
of miles from his required landing-place.

Quite recently Mr. Alexander Gross, the well-known maker of
aviation instruments, who is even more famous for his excellent
aviation maps, claims to have produced an anti-drift
aero-compass, which has been specially designed for use on
aeroplanes.  The chief advantages of this compass are that the
dial is absolutely steady; the needle is extremely sensitive and
shows accurately the most minute change of course; the anti-drift
arrangement checks the slightest deviation from the straight
course; and it is fitted with a revolving sighting arrangement
which is of great importance in the adjustment of the instrument.

Before the airman leaves Earth he sets his compass to the course
to be steered, and during the flight he has only to see that the
two boldly-marked north points--on the dial and on the outer
ring--coincide to know that he is keeping his course.  The north
points are luminous, so that they are clearly visible at night.

It is quite possible that if some of our early aviators had
carried such a highly-efficient compass as this, their lives
might have been saved, for they would not have gone so far astray
in their course.  The anti-drift compass has been adopted by
various Governments, and it now forms part of the equipment of
the Austrian military aeroplane.

When undertaking cross-country flights over strange land an
airman finds his way by a specially-prepared map which is spread
out before him in an aluminium map case.  From the illustration
here given of an aviator's map, you will see that it differs in
many respects from the ordinary map.  Most British aviation maps
are made and supplied by Mr Alexander Gross, of the firm of
"Geographia", London.

Many airmen seem to find their way instinctively, so to speak,
and some are much better in picking out landmarks, and
recognizing the country generally, than others.  This is the case
even with pedestrians, who have the guidance of sign-posts,
street names, and so on to assist them.  However accurately some
people are directed, they appear to have the greatest difficulty
in finding their way, while others, more fortunate, remember
prominent features on the route, and pick out their course as
accurately as does a homing pigeon.

Large sheets of water form admirable "sign-posts" for an airman;
thus at Kempton Park, one of the turning-points in the course
followed in the "Aerial Derby", there are large reservoirs, which
enable the airmen to follow the course at this point with the
greatest ease.  Railway lines, forests, rivers and canals, large
towns, prominent structures, such as gasholders, chimney-stalks,
and so on, all assist an airman to find his way.

CHAPTER XLIII
The First Airman to Fly Upside Down

Visitors to Brooklands aerodrome on 25th September, 1913, saw one
of the greatest sensations in this or any other century, for on
that date a daring French aviator, M. Pegoud, performed the
hazardous feat of flying upside down.

Before we describe the marvellous somersaults which Pegoud made,
two or three thousand feet above the earth, it would be well to
see what was the practical use of it all.  If this amazing airman
had been performing some circus trick in the air simply for the
sake of attracting large crowds of people to witness it, and
therefore being the means of bringing great monetary gain both to
him and his patrons, then this chapter would never have been
written.  Indeed, such a risk to one's life, if there had been
nothing to learn from it, would have been foolish.

No; Pegoud's thrilling performance must be looked at from an
entirely different standpoint to such feats of daring as the
placing of one's head in the jaws of a lion, the traversing of
Niagara Falls by means of a tight-rope stretched across them, and
other similar senseless acts, which are utterly useless to
mankind.

Let us see what such a celebrated airman as Mr. Gustav Hamel said
of the pioneer of upside-down flying.

"His looping the loop, his upside-down flights, his general
acrobatic feats in the air are all of the utmost value to pilots
throughout the world.  We shall have proof of this, I am sure, in
the near future.  Pegoud has shown us what it is possible to do
with a modern machine.  In his first attempt to fly upside down
he courted death.  Like all pioneers, he was taking liberties
with the unknown elements.  No man before him had attempted the
feat.  It is true that men have been upside down in the air; but
they were turned over by sudden gusts of wind, and in most cases
were killed.  Pegoud is all the time rehearsing accidents and
showing how easy it is for a pilot to recover equilibrium
providing he remains perfectly calm and clear-headed.  Any one of
his extraordinary positions might be brought about by adverse
elements.  It is quite conceivable that a sudden gust of wind
might turn the machine completely over.  Hitherto any pilot in
such circumstances would give himself up for lost.  Pegoud has
taught us what to do in such a case. . . . his flights have given
us all a new confidence.

"In a gale the machine might be upset at many different angles. 
Pegoud has shown us that it is easily possible to recover from
such predicaments.  He has dealt with nearly every kind of
awkward position into which one might be driven in a gale of
wind, or in a flight over mountains where air-currents prevail.

"He has thus gained evidence which will be of the utmost value to
present and future pilots, and prove a factor of signal
importance in the preservation of life in the air."

Such words as these, coming from a man of Mr. Hamel's reputation
as an aviator, clearly show us that M. Pegoud has a life-saving
mission for airmen throughout the world.

Let us stand, in imagination, with the enormous crowd of
spectators who invaded the Surrey aerodrome on 25th September,
and the two following days, in 1913.

What an enormous crowd it was!  A line of motor-cars bordered the
track for half a mile, and many of the spectators were busy city
men who had taken a hasty lunch and rushed off down to Weybridge
to see a little French airman risk his life in the air. 
Thousands of foot passengers toiled along the dusty road from the
paddock to the hangars, and thousands more, who did not care to
pay the shilling entrance fee, stood closely packed on the high
ground outside the aerodrome.

Biplanes and monoplanes came driving through the air from Hendon,
and airmen of world-wide fame, such as Sopwith, Hamel, Verrier,
and Hucks, had gathered together as disciples of the great
life-saving missionary.  Stern critics these!  Men who would
ruthlessly expose any "faked" performance if need were!

And where is the little airman while all this crowd is gathering? 
Is he very excited?  He has never before been in England.  We
wonder if his amazing coolness and admirable control over his
nerves will desert him among strange surroundings.

Probably Pegoud was the coolest man in all that vast crowd.  He
seemed to want to hide himself from public gaze.  Most of his
time, was taken up in signing post-cards for people who had been
fortunate enough to discover him in a little restaurant near
which his shed was situated.

At last his Bleriot monoplane was wheeled out, and he was
strapped, or harnessed, into his seat.  "Was the machine a
'freak' monoplane?" we wondered.

We were soon assured that such was not the case.  Indeed, as
Pegoud himself says:  "I have used a standard type of monoplane
on purpose.  Almost every aeroplane, if it is properly balanced,
has just as good a chance as mine, and I lay particular stress on
the fact that there is nothing extraordinary about my machine, so
that no one can say my achievements are in any way faked."

During the preliminary operations his patron, M. Bleriot, stood
beside the machine, and chatted affably with the aviator.  At
last the signal was given for his ascent, and in a few moments
Pegoud was climbing with the nose of his machine tilted high in