# A B C D E F G H I J K L M N O P Q R S T U V W Y Z
Spring Sails
SAILS constructed with SHUTTERS which turn after the fashion of the slats in a venetian blind, linked to a spring, the tension of which can be set manually so that the shutters will open & close according to wind strength, in order to control the power produced. An early form of shuttered sail introduced in 1772. (devised by Andrew Miekle).