these details. When children come into the library we put the
inkstand and the watch on the high shelf until they be a little
older."

About the year 1870 a young German engineer, named Otto
Lilienthal, began some experiments with a motorless glider, which
in course of time were to make him world-famed. For nearly
twenty years Lilienthal carried on his aerial research work in
secrecy, and it was not until about the year 1890 that his
experimental work was sufficiently advanced for him to give
demonstrations in public.

The young German was a firm believer in what was known as the
"soaring-plane" theory of flight. From the picture here given we
can get some idea of his curious machine. It consisted of large
wings, formed of thin osiers, over which was stretched light
fabric. At the back were two horizontal rudders shaped
somewhat like the long forked tail of a swallow, and over these
was a large steering rudder. The wings were arranged around the
glider's body. The whole apparatus weighed about 40 pounds.

Lilienthal's flights, or glides, were made from the top of a
specially-constructed large mound, and in some cases from the
summit of a low tower. The "birdman" would stand on the top of
the mound, full to the wind, and run quickly forward with
outstretched wings. When he thought he had gained sufficient
momentum he jumped into the air, and the wings of the glider bore
him through the air to the base of the mound.

To preserve the balance of his machine--always a most difficult