I am asked to set forth the development of the "two-surface" type of
flying machine which is now used with modifications by Wright Brothers,
Farman, [1]Delagrange, Herring and others.
This type originated with Mr. F. H. Wenham, who
patented it in England in 1866 (No. 1571), taking out provisional papers
only. In the abridgment of British patent Aeronautical Specifications
(1893) it is described as follows:
"Two or more aeroplanes are arranged one above the other, and
support a framework or car containing the motive power. The aeroplanes
are made of silk or canvas stretched on a frame by wooden rods or steel
ribs. When manual power is employed the body is placed horizontally,
and oars or propellers are actuated by the arms or legs.
"A start may be obtained by lowering the legs and running down
hill or the machine may be started from a moving carriage. One or more
screw propellers may be applied for propelling when steam power is
employed.
On June 27, 1866, Mr. Wenham read before the "Aeronautical
Society of Great Britain," then recently organized, the ablest paper
ever presented to that society, and thereby breathed into it a spirit
which has continued to this day. In this paper he described his
observations of birds, discussed the laws governing flight as to the
surfaces and power required both with wings and screws, and he then gave
an account of his own experiments with models and with aeroplanes of
sufficient size to carry the weight of a man.
