WIN 
Velocity of the 
wind. 
Perpendi- 
-nlar force 
on one sq. 
foot, in 
rtverdupoi? 
pounas. 
Wiles 
ill one 
hour. 
= feet 
in one 
second. 
1 , 
1.47 
.005 
2 
2.93 
.020 
3 
4.40 
.044 
4 
5.87 
.079 
5 
7.33 
.123 
10 
14.67 
.492 
15 
22.00 
1.107 
20 
29.34 
1.968 
25 
36.67 
3.075 
30 
44.01 
4.429 
35 
51.34 
6.027 
40 
58.68 
7.873 
45 
66.01 
9.963 
50 
73.35 
12.300 
60 
88.02 
17.715 
80 
117.36 
31.490 
100 
146.70 
49.200 
Common appellations of 
the wind. 
Hardly percepti- 
ble. 
^ Just perceptible. 
? Gentle pleasant 
^ wind. 
? Pleasant brisk 
S gale- 
^ Very brisk. 
^ High winds. 
^ Very liigli. 
A storm or tem- 
pest. 
A great storm. 
A imrricaBe. 
f A hurricane that 
I tears up trees, 
< and carries 
buildings, &c. 
L before it. 
The force of the wind is nearly as the 
square of the velocity, or but little above 
it, in these velocities. But the force is 
much more than in the simple ratio of the 
surfaces, with the same velocity, and this 
increase of the ratio is the more, as the ve- 
locity is the more. By accurate experi- 
ments with two planes, the one of I7a 
square inches, the other of 32, which are 
nearly in the ratio of 5 to 9. Dr. Hutton 
found their resistances, with a velocity of 
20 feet per second, to be the one, 1.196 
ounces, and the other, 2.542 ounces ; which 
are in the ratio of 8 to 17, being an increase 
of between one-flfth and one-sixth parts 
more than the ratio of the surfaces. 
WINDLASS, a machine used to raise 
heavy weights withal, as guns, stones, an- 
chors, &c. It is very simple, consisting 
only of an axis, or roller, supported hori- 
zontally at the two ends, by two pieces of 
wood and a pulley : the trvo pieces of wood 
meet at top, being placed diagonally, so as 
to prop each other ; the axis, or roller, goes 
through the two pieces, and turns in them. 
The pully is fastened at top where tlie 
pieces join. Lastly, there are two sfaves 
or handspikes go through the roller, where- 
by it is turned, and the rope which comes 
over the pulley is wound off and on the 
same. 
WIN 
Windlass, in a ship, is an instrument in 
small ships, placed upon the deck, just abaft 
the foremast. It is made of a piece of tim- 
ber six or eight feet square, in form of an 
axle-tree, whose length is placed horizon- 
tally upon two pieces of wood at tlie ends 
thereof, and upon which it is turned about 
by the help of handspikes put into holes 
made for that purpose. This instrument 
serves for weighing anchors, or hoisting of 
any weight, in or out of the ship, and will 
purchase much more than any capstan, and 
tliat williout any danger to those that 
heave; for if in heaving the windlass about, 
auy of the hamlspikes should happen to 
break, the windlass would pall of itself. 
AVINDMILL, a kind of mill, the inter- 
nal pai ts of which are much the same with 
those of a water-mill ; from Which, however, 
it differs, in being moved by the impulse of 
the wind upon its vanes or sails, which are to 
be considered as a wheel on the axle. Plate, 
Windmill, is a vertical section of a windmill 
of that kind, which is called a smock-mill, 
j. e. when the building, the mill, and niaclit- 
nerv are fixed, and the head of the mill sup- 
portii g the axis of the sails turns round upon 
it. A A are the walls of the mill-house, which 
is longer one .way than the other, and the 
section is through the shortest side ; in this 
direction it will but just contain the machi- 
nery, and leave a passage; in the other 
direction the house is longer, and is used as 
a warehouse to stow the corn and flour. 
The roof of the house is framed of large 
beams, a flooring is laid on these beams, 
and then the whole is covered with sheet 
lead. Eight long upright beams, B B, are 
framed into the roof of the house, and dis- 
posed round in a circle; at the upper angle 
they support a circular kirb, D D ; the 
eight uprights, B B, are braced by cross 
pieces framed between them, so as to ren- 
der the whole building very staunch ; the 
outside is covered with weather-board, just 
to shoot off tlie rain, but open enough to 
admit the wind to pass freely through the 
house. Upon the upper fixed kirb, D D, 
thirty-six rollers are placed (two of them are 
seen in the section) ; these rollers turn in mor- 
tices, cut through a circular ring of wood, 
which keeps the thirty-six rollers in their 
places, and at their proper distances fi om 
one another. The rollers support another 
circular w’ooden ring, a a, on which the 
head of the mill is framed. This framing 
consists of two beams, b, halved into the 
ring, parallel to the main axis of the sails, 
and including the great cog wheel between 
