from
The Collaborative International Dictionary of English v.0.48
Beaufort's scale \Beau"fort's scale`\ (Meteor.)
A scale of wind force devised by Sir F. Beaufort, R. N., in
1805, in which the force is indicated by numbers from 0 to
12.
[1913 Webster]
Note: The full scale is as follows: -- 0, calm; 1, light air;
2, light breeze; 3, gentle breeze; 4, moderate breeze;
5, fresh breeze; 6, strong breeze; 7, moderate gale; 8,
fresh gale; 9, strong gale; 10, whole gale; 11, storm;
12, hurricane.
[Webster 1913 Suppl.]