ointed out that his calculations made no
allowance for the slackening of the upward pace of the balloon as it
neared its limit, nor for the time it would take, with the valve feebly
pulled, to change its direction and acquire speed in its descent. They
are inclined to allow him a height of about six miles, which is a
sufficiently remarkable achievement.

All these ascents, though they proved that the balloon had a certain
utility for the exploration of the upper reaches of the atmosphere, did
little or nothing for aerial navigation. The great vogue of the balloon
distracted attention from the real problem of flight. That problem was
not abandoned; a number of men, working independently, without any sort
of public recognition, made steady advance during the whole course of
the nineteenth century. By the end of the century, three years before
flight was achieved, those who were most deeply concerned in the attempt
knew that success was near. The great difficulty of scientific research
lies in choosing the right questions to ask of nature. Every lawyer
knows that it is easy to put a question so full of false assumptions
that no true answer to it is possible; and many a laborious man of
science has spent his life in framing such questions, and in looking for
an answer to them. The contribution of the nineteenth century to the
science of flight was that it got hold of the right questions, and
formulated them more or less exactly, so that the answers, when once
they were supplied by continued observation and experiment, were things
of value.

The earliest of these pioneers was Sir George Cayley, a country
gentleman with estates in Yorkshire and Lincolnshire, who devoted his
life to scientific pursuits. He was born in 1773, and the balloons which
excited the world during his boyhood directed his mind to the subject of
aerial navigation. He invented many mechanical contrivances, and he laid
great and just stress on the importance of motive power for successful
flight. In 1809 he published, in _Nicholson's Journal_, a paper on
Aerial Navigation, which has since become a classic, for although it
stops short of a complete exposition, it is true so far as it goes, and
contains no nonsense and no fantasy. He endeavoured, in the first year
of Queen Victoria's reign, to establish an aeronautical society, but the
ill repute of the balloon and the bad company it kept deprived him of
influential support. He did his duty by his county, a