#beaufort scale

[emmaklee]

[noosphe-re]

Beaufort scale

[ltwilliammowett]

Sailing Wind Pressure- Beaufort Scale

[klavier]

beaufort scales on land and sea

[ltwilliammowett]

“Storm Warning” and “Beaufort Scale” flags on silk, by Eric Holch (1948-)

[ltwilliammowett]

... windy, windier, windiest! von James Vaughan

The Beaufort Scale first published 1832, by Sir Francis Beaufort in a Nautical Magazine of the Admiralty - this one shown here is a version of the 1940s

[ltwilliammowett]

The Beaufort scale

The Beaufort scale is a very important scale and still valid today, it defines the wind and classifies the wind speeds in 13 units. This scale was developed by Rear Admiral Sir Francis Beaufort. Whereby he cannot be regarded as the inventor of a wind scale, because before him Tycho Brage (1546- 1601), a Danish nobleman and astronomer, already tried to categorize the wind, and the engineer John Smeaton created a scale on the basis of windmill wings in 1759. This scale contained 9 wind forces - without calm - and referred to the wind forces on land. The then hydrograph of the "East India Company" and from 1795 First Hydrograph of the Admiralty, Alexander Dalrymple, made Smeaton's scale famous in seafaring. Dalrymple's version contained twelve wind forces (again without calm), ranging from 1 "weak draft" to 12 "storm". Dalrymple published his own scale, expressly intended for use in logbooks, in a brochure in 1779 and in the book Practical Navigation in 1790.

Sir Francis Beaufort, by Stephen Pearce, 1850

Francis Beaufort probably got to know Dalrymples Skala already through his brochure of 1779. From the age of 14 he himself served the East India Company and later the Royal Navy and kept an extensive diary throughout his life, in which he recorded, among other things, the weather. On 12 or 13 January 1806 he entered the words here: "From now on I will estimate the strength of the wind according to the following scale, for nothing conveys a more unclear idea of wind and weather than the old expressions moderate and cloudy, etc. etc.". A scale from 1 to 13 follows, ranging from "calm" to "storm". On September 14, 1807, he created a new diary in which he - as usual - noted on the endpaper the wind scale he intended to use. Shortly thereafter he improved the scale by adding how the wind force could be seen on the sails of a fully rigged frigate. Wind force 5, for example, prevails when the mainsail, brakesail, royal, aviator and staysail can remain hoisted, while at wind force 7 the three uppermost sails must be reefed.

After Beaufort had become hydrograph of the Admiralty in 1829, he passed on his improved scale to all who were interested. It was published in 1832 in the Nautical Magazine of the Admiralty. By 1837 the scale was already in use throughout the surveying service, and at the end of 1838 the Admiralty issued an instruction making it mandatory. However, this scale had no name and was only called the "attached scheme". Also in the detailed obituaries on the occasion of Beaufort's death no wind scale is mentioned at all. This name was given only 1906 by the British weather service and the version of the scale had 13 steps (incl. 0). Here, wind force 0, i.e. calm, is characterized by smoke rising vertically. At wind force 2, a "light breeze", the wind becomes noticeable on the face and leaves rustle. The respective wind speed is given for this purpose. In this version, the Beaufort scale has been included in numerous dictionaries and encyclopaedias.

Beaufort-Scale-by-Pat-Royce

In 1927 the German captain Peter Petersen reformulated the original Beaufort scale for seafaring purposes, because sails no longer played a major role in shipping. The Petersen Sea Scale describes the effect of wind on the sea. Thus, at wind force 6, "strong wind", large waves of 2.5 to 4 meters height form, everywhere are extensive, white foam combs to be seen; there is some spray. In 1935, the Beaufort scale was accepted as generally valid at the First International Meteorological Conference in Brussels and in 1946, by decision of the International Meteorological Organization, was extended by a further 5 to a total of 18 levels (incl. 0). In 1970 it was reduced again to 12, the 18 scale is only valid in Taiwan and the Chinese mainland.

[ub-sessed]