Born in Ireland in 1774, Francis Beaufort, later to become an Admiral of the UK fleet, began to develop his famous wind scale during the early years of the 19th century. It is thought that Francis first finalised his original scale around 1805, although it was initially used simply as a personal aid.
It was not until 1832 that the first reference to this scale appeared in any publication and it was to be a further six years before the Beaufort scale caught the attention of the British Navy. On 28 December 1838 a memorandum was issed to all naval seagoing vessels, which instructed that within a ships log book there should appear two columns “wherein the force of the wind and the appearance of the atmosphere” was to be registered every hour.
The initial Beaufort scale was, as defined within the admiralty notice, a simple two column configuration. In the first column would be recorded a scale from 1 to 12 and the second defining that scale, with 0 being equal to calm and 12 denoting storm force conditions. In between these were various other wind conditions from light breeze (3) to Brisk gale (9). As an aide to sailors, Beaufort also added a description of the type of canvas that ships should use if confronted with any of these scaled conditions. For example, Beaufort scale five would require “Royals etc,” whereas number eleven on the scale would need storm staysails.
Since its introduction into official use, the Beaufort scale has undergone a number of revisions. In the earlier revisions, the adjustments were made simply to make the scale more appropriate to the type of rigging and sails being used. However, in 1903, a major change saw a scale that would be equated to wind speeds being introduced.
Although it quickly became the accepted method for calculating wind and its effects, the Beaufort scale was not the first scale of its kind, with records showing that simplified versions existed much earlier. However, until recently it has been the most influential scale of its kind adopted by meteorologists throughout the world, and much used in the naval and shipping environments. Another alteration took place in 1939 when, to take into account the change from sail to power, the surface effect and appearance at the varying wind speeds was taken into account.
Although the scale was extended in 1944, with a further five points added to deal with wind speeds between the 64 knots on the scale number twelve and 118 knots, which was subsequently referred to as scale number seventeen, for all normal shipping purposes the original 12 point scale has remained the same ever since it was originally introduced.
Sources:
The scale can be seen at http://www.spc.noaa.gov/faq/tornado/beaufort.html
http://www.metoffice.gov.uk/education/secondary/students/beaufort.html
