*beaufort'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 ]

☞ 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. ]