(obsolete) A child's hornbook for learning the alphabet. 1802, William Hutton, The History of the Roman Wall, preface You will also pardon the errors of the Work, for you know I was not bred to letters; but, that the battledore, at an age not exceeding six, was the last book I used at school. (obsolete) A bat or beetle used in washing clothes.
The parachute, like the helicopter and the hang glider, dates back to the drawings of mankind's greatest public genius, Leonardo da Vinci.
It works on the basic principle of 'air resistance' and 'gravity', and is used in rescue work, recreational activities and extreme sports. The fabric canopy, suspension lines and support tapes are the main components of a parachute; and all of these are made from specialized material. When the parachute is deployed, air gets trapped inside the canopy, thus making the parachute fabric stretch outwards and resist the fall.