meeting of the Society under the Presidency of the Duke of
Argyll, when in June, at the Society of Arts, Francis Herbert
Wenham read his now classic paper Aerial Locomotion. Certain
quotations from this will show how clearly Wenham had thought
out the problems connected with flight.

'The first subject for consideration is the proportion of
surface to weight, and their combined effect in descending
perpendicularly through the atmosphere. The datum is here based
upon the consideration of safety, for it may sometimes be
needful for a living being to drop passively, without muscular
effort. One square foot of sustaining surface for every pound
of the total weight will be sufficient for security.

'According to Smeaton's table of atmospheric resistances, to
produce a force of one pound on a square foot, the wind must
move against the plane (or which is the same thing, the plane
against the wind), at the rate of twenty-two feet per second, or
1,320 feet per minute, equal to fifteen miles per hour. The
resistance of the air will now balance the weight on the
descending surface, and, consequently, it cannot exceed that
speed. Now, twenty-two feet per second is the velocity acquired
at the end of a fall of eight feet--a height from which a
well-knit man or animal may leap down without much risk of
injury. Therefore, if a man with parachute weigh together 143
lbs., spreading the same number of square feet of surface
contained in a circle fourteen and a half feet in diameter, he
will descend at perhaps an unpleasant velocity, but with safety
to life and limb.