was to an
ocean-going steamer or as a road was to the automobile.

Requisites of Flying Machine.

Flying machines were commonly divided into monoplanes and biplanes,
according as they had one or two supporting surfaces. The distinction
was not, however, fundamental. To get the requisite strength some
form of girder framework was necessary, and it was a mere question of
convenience whether the supporting surface was arranged along both
the top and the bottom of this girder, or along the bottom only. The
framework adopted universally was of wood braced by ties of pianoforte
wire, an arrangement giving the stiffness desired with the least
possible weight. Some kind of chassis was also necessary.

CHAPTER XXIII. AMATEURS MAY USE WRIGHT PATENTS.

Owing to the fact that the Wright brothers have enjoined a number of
professional aviators from using their system of control, amateurs have
been slow to adopt it. They recognize its merits, and would like to use
the system, but have been apprehensive that it might involve them in
litigation. There is no danger of this, as will be seen by the following
statement made by the Wrights:

What Wright Brothers Say.

"Any amateur, any professional who is not exhibiting for money, is at
liberty to use our patented devices. We shall be glad to have them do
so, and there will be no interference on our part, by legal action, or
otherwise. The only men we proceed against are those who, without our
permission, without even asking our consent, coolly appropriate the
results of our labors and use them for the purpose of making money.
Curtiss, Delagrange, Voisin, and all the rest of them who have used our
devices have done so in money-making exhibitions. So long as there
is any money to be made by the use of the products of our brains, we
propose to have it ourselves. It is the only way in which we can get
any return for the years of patient work we have given to the problem of
aviation. On the other hand, any man who wants to use these devices for
the purpose of pleasure, or the advancement of science, is welcome to do
so, without money and without price. This is fair enough, is it not?"

Basis of the Wright Patents.

In a flying machine a normally flat aeroplane having lateral marginal
portions capable of movement to different positions above or below the
normal plane of the body of the aeroplane, such movement being about
an axis transverse to the line of flight, whereby said latera