Page:Aerial Flight - Volume 1 - Aerodynamics - Frederick Lanchester - 1906.djvu/171

Rh geometrically similar for different load values; in fact, it will be hereafter shown that it is not.

We will in the first instance direct our attention to the case where the load is supposed to be very small indeed, so small in fact as not to be measurable in finite units, a small quantity of the second order.

In order that there shall be no ambiguity in respect of the proposed conditions, let us imagine a number of aerofoils of equal area carrying different loads that vary from some finite value down to zero, and suppose that each aerofoil is of the best form possible for deriving the support necessary from the atmosphere. Then the form of the aerial disturbance may vary in the different cases, but as the load approaches zero the aerofoil approximates more and more closely to an aeroplane, and the