Page:Aerial Flight - Volume 1 - Aerodynamics - Frederick Lanchester - 1906.djvu/381

Rh shown in the case of the curves $$A$$ and $$B ,$$ whilst the curve $$C$$ shows that for planes of this particular proportion and aspect the curve for small angles approximates very closely to the law $$V^2 \times \beta =$$ constant. The theoretical curve is given by the dotted line showing the degree of approximation. This law has already been given in the form—

$$\beta \propto \frac{1}{V^2}$$ (§ 152 (e)).

Fig. 99 (Chap. VI.) is an example taken from the Memoir (Fig. 10), giving the $$P_\beta / P_{90}$$ relationship for changes in $$\beta$$ value, as determined by means of the present appliance.

Fig. 149 is also a plotting (Fig. 11 of the Memoir), showing the direct determination of the horizontal component. The small circles represent the actual observations, and the crosses give points calculated on the basis of a simple resolution of