tion" day, will disclose several marked differences in
construction between the modern type and the earlier Wright machine,
though the central idea is the same.

CHAPTER XXVI. How the Wrights launched their Biplane

Those of us who have seen an aeroplane rise from the ground know that
it runs quickly along for 50 or 60 yards, until sufficient momentum has
been gained for the craft to lift itself into the air. The Wrights,
as stated, fitted their machine with a pair of launching runners which
projected from the under side of the lower plane like two very long
skates, and the method of launching their craft was quite different from
that followed nowadays.

The launching apparatus consisted of a wooden tower at the starting end
of the launching ways--a wooden rail about 60 or 70 feet in length.
To the top of the tower a weight of about 1/2 ton was suspended. The
suspension rope was led downwards over pulleys, thence horizontally to
the front end and back to the inner end of the railway, where it was
attached to the aeroplane. A small trolley was fitted to the chassis of
the machine and this ran along the railway.

To launch the machine, which, of course, stood on the rail, the
propellers were set in motion, and the 1/2-ton weight at the top of
the tower was released. The falling weight towed the aeroplane rapidly
forward along the rail, with a velocity sufficient to cause it to glide
smoothly into the air at the other end of the launching ways. By an
ingenious arrangement the trolley was left behind on the railway.

It will at once occur to you that there were disadvantages in this
system of commencing a flight. One was that the launching apparatus was
more or less a fixture. At any rate it could not be carried about from
place to place very readily: Supposing the biplane could not return to
its starting-point, and the pilot was forced to descend, say, 10 or 12
miles away: in such a case it would be necessary to tow the machine back
to the launching ways, an obviously inconvenient arrangement, especially
in unfavourable country.

For some time the "wheeled" chassis has been in universal use, but in
a few cases it has been thought desirable to adopt a combination of
runners and wheels. A moderately firm surface is necessary for the
machine to run along the ground; if the ground be soft or marly the
wheels would sink in the soil, and serious accidents have resulted from
the sudden stoppage of the forward motion due