[32] In the Wright machine r.p.m. = 450; in Blériot XI. r.p.m. = 1350.
[33] Such propellers, however, require a considerable amount of rubber.
[34] But see also § 22.
[35] "Flight," March 10, 1910. (Illustration reproduced by permission.)
[36] According to the author's views on the subject.
[37] Nevertheless some models with a very low aspect ratio make good flyers, owing to their extreme lightness.
[38] The chief advantage of cane—its want of stiffness, or facility in bending—is for some parts of the machine its chief disadvantage, where stiffness with resilience is most required.
[39] This is a good plan—not a rule. Good flying models can, of course, be made in which this does not hold.
[40] This is in theory only: in practice the monoplane holds both records.
[41] The best position for the propellers appears to be one in front and one behind, when extreme lightness is the chief thing desired.