The Beaufort Wind Scale for estimating wind speed was developed in 1805 by Admiral Sir Francis Beaufort. It was originally used for estimating wind velocity by noting the effects of winds an the sails of British Navy sailing ships. It was found to be so valuable that it was later modified for use on land.
Smoke rises vertically.
1 1-3 Light Air Direction of wind is shown by smoke drift, but not by wind vane. Slight Breeze Wind felt on face, leaves rustle, ordinary vane moved by wind. 3 8-12 Gentle Breeze Leaves and small twigs in constant motion, wind extends light flags. 4 13-18 Mod. Breeze Raises dust and loose paper, small branches are moved.