Forefather of the Beaufort Table
Since the XVI or early XVII centuries, the table of
the Portuguese pilot Gaspar Manuel (circa 1604) was prepared as a function of
the action of wind on a vessel of the India run. The pilot called it:
“Leagues that a vessel of
the ones of the career of India, will be able to make according to the wind
that carries her. “
This is the first known table
for the classification of wind. The one below includes conversions for miles
and knots.
|
Wind |
Singradura
(leagues/24hrs) |
Singradura
(nm/24hrs) |
Speed of
nau
in knots |
||||
|
Old Name
|
Beaufort
|
Beam |
Stern |
Beam |
Stern |
Beam |
Stern |
|
De governo (.gov) |
Calm |
8 |
10 |
25,6 |
32 |
1,1 |
1,3 |
|
Calmo |
Light |
12-14 |
14-16 |
38,4-44,8 |
44,8-52,1 |
1,6-1,9 |
1,9-2,1 |
|
Bonança |
Gentle |
16-17,5 |
18-20 |
51,2-56 |
57,5-64 |
2,1-2,3 |
2,4-2,7 |
|
Galerno |
Moderate |
20-22 |
24-26 |
64-70,4 |
76,8-83,2 |
2,7-2,9 |
3,2-3,5 |
|
Fresco |
Fresh |
25 |
30 |
80 |
96 |
3,3 |
4 |
|
Esperto (smart) |
Strong |
20-30 |
33-35 |
89,6-96 |
105,6-112 |
3,7-4 |
4,4-4,7 |
|
Teso (stiff) |
Gale |
32-34 |
36-38 |
102,4-108,8 |
115,2-121,6 |
4,3-4,5 |
4,8-5,1 |
|
Ventante (windy) |
Storm |
38-40 |
43-45 |
121,6-128 |
137,6-144 |
5,1-5,3 |
5,7-6 |
|
In 1805 the Irish Admiral
Sir Francis Beaufort (1774-1857), in the service of the English navy,
idealized a table that scaled the force of the wind in 12 parts, having this
been recognized for the English Admiralty in 1838 and adopted by the International
Meteorological Committee in 1874. |
|