CHAPTER V.

PROPELLERS OR SCREWS.

§ 1. The position of the propeller. § 2. The number of blades. § 3. Fan _versus_ propeller. § 4. The function of a propeller. § 5. The pitch. § 6. Slip. § 7. Thrust. § 8. Pitch coefficient (or ratio). § 9. Diameter. § 10. Theoretical pitch. § 11. Uniform pitch. § 12. How to ascertain the pitch of a propeller. § 13. Hollow-faced blades. § 14. Blade area. § 15. Rate of rotation. § 16. Shrouding. § 17. General design. § 18. The shape of the blades. § 19. Their general contour--Propeller design--How to design a propeller. § 20. Experiments with propellers--Havilland's design for experiments--The author experiments on dynamic thrust and model propellers generally. § 21. Fabric-covered screws. § 22. Experiments with twin propellers. § 23. The Fleming Williams propeller. § 24. Built-up _v._ twisted wooden propellers 52