CHAPTER II.

THE QUESTION OF RESISTANCE.

§ 1. The chief function of a model in the medium in which it travels. § 2. Resistance considered as load percentage. § 3. How made up. § 4. The shape of minimum resistance. § 5. The case of rubber-driven models. § 6. The aerofoil surface--Shape and material as affecting this question. § 7. Skin friction--Its coefficient. § 8. Experimental proofs of its existence and importance 7