a an at ac Rs RS NE A 
WIND. 
Velocity of the Wind. Perpendicular Force on one 
Miles Feet square Foot in Avoirdupois 
per Hour. per Second. Pounds and Parts. 
1 1.47 7005 Hardly perceptible. 
9 
re aoe Just perceptible. 
5.87 079 
5 7.33 "193 Gently pleasant. 
10 14.6 492 : 
15 99. 7 1.107 Pleasant, brisk. 
20 29.34 1.968 POI 
25  . 36.67 Bovey Wey inks, 
30 44,01 AAD ON ee 
35 51.84 e027. Hishowind: 
40 58.68 7.873 WV tome ae 
AB 66.01 Sane Very high wind. 
50 73.39 12.300 Storm or tempest. 
60 88.02 17.715 Great storm. 
80 117.36 31.490 Hurricane. 
Hurricane that tears up trees, 
100 146.7 49.200 and carries buildings be- 
fore it. 
Currents thus produced may be permanent and 
general, extending over a large portion of the 
globe; periodical, as in the Indian ocean, or 
variable and occasional, or, at least, uncertain, 
as the winds in temperate climates. General or 
permanent winds blow always nearly in the same 
direction, and are called trade-winds. On the 
north of the equator, their direction is from the 
north-east (varying at times a point or two of the 
compass each way): on the south of the equator, 
| they proceed from the south-east.—See AwNE- 
MOMETER, WEATHER, and CALENDAR. 
WIND. The breathing of any animal, parti- 
cularly of the horse. The most effectual method 
of bringing a horse into the peculiarly healthy 
habit of breathing technically called good wind, 
is to give him regular exercise, to increase very 
gradually the amount of exercise, to give him 
oats and good hay in quantity proportioned to 
his exercise, to make his allowance of: hay at all 
times moderate, to give him water in moderate 
quantity three times a-day, to keep his stable in 
a clean and well-ventilated condition, and to give 
him occasionally or when needed a dose or two 
of mild physic. The nature and varieties and 
proper treatment of morbidity in a horse’s habit 
of breathing are treated in the articles Broxun 
Winn, Turck Wriyp, and PNEumontiA. 
WIND-FLOWER. Themarsh gentian and the 
anemone. See the articles Gunrian and ANEMONE. 
WIND-GALLS. Elastic tumours on each side 
of the back sinews of the horse, immediately 
above the fetlock joint. They are generally 
caused by hard work at too early an age; and 
they arise from excessive secretions of the synovial 
fluid, which lubricates the joints and bony pro- 
minences of the limbs. They are called durse 
mucose by scientific veterinarians; but both this 
name and the popular one are misnomers; for 
they contain neither mucus nor wind, but are 
simply enlarged capsules of synovia. They sel- 
dom occasion much suffering or inconvenience, 
and can scarcely be regarded as decided indica- 
tions of unsoundness; but are commonly slow, 
chronic, painless enlargements. They may be 
partially subdued by means of blisters, stimu- 
lating liniments, firing, or appliances of any 
WINDMILL. 
kind for promoting the absorption of their con- 
tents; but they are best dealt with by the mere 
pressure of bandage,—or at the utmost by the 
combination of this with an evaporating lotion ; 
and never ought they, according to the practice 
of the old farriers, to be opened and surgically 
evacuated,—for the laying of them open occasions 
almost as much irritation and danger as if the 
joint itself were to be perforated. 
WINDMILL. A mill whose moving power is 
the wind. It is fitted with arms, vanes, or sails, 
for catching the breeze, and may have them 
either vertically or horizontally, and admits of 
a considerable diversity of both structure and 
adaptation. Windmills with vertical sails are 
the best; but even they, no matter how well 
constructed or how advantageously situated, are 
far inferior, in aggregate value, to water-mills or 
steam-mills, and are not equal, in some cases, to 
even horse-mills or hand-mills. They suit toler- 
ably well on only exposed spots, where every cur- 
rent in the air can be caught; and even there 
they have the incurable defect of being perfectly 
useless in calm weather, and sometimes therefore 
at a season when mill-work is most wanted, and 
cannot without loss and great inconvenience be 
postponed. Mr. Ferguson calculated the velocity 
of the sails of a windmill, in a moderate wind, to 
be 30 miles per hour. 
As a horizontal windmill consists of vertical 
sails moving horizontally round a vertical arbour 
or windshaft, no motion would arise on exposing 
it to the action of the wind, as the effect of the 
wind upon the sails on one side would be coun- 
terbalanced by its action upon the corresponding 
sails ‘on the opposite side. Hence it is necessary 
either to screen the sails on one side from the 
action of the wind, or to construct the sails in 
such a manner that, when they return against 
the wind, they present only their edge to its ac- 
tion. The method of screening the returning 
sails from the wind is adopted in Tartary and 
some provinces of Spain, and is the most simple 
that has been tried. When the screen is not 
used, the sails may be fixed like float-boards, 
with hinges, on the circumference of a large 
drum or cylinder, so that, when they are to re- 
ceive the action of the wind, they stand at right 
angles to the drum, and when they turn against 
the wind, they fold down upon its circumference. 
Other ingenious methods have also been devised 
for bringing back the sails against the wind. In 
the vertical windmill, on the other hand, the 
arms which carry the sails revolve in a plane 
facing the wind. In this arrangement, if the 
sails were in the same plane with the arms, the 
wind would fall perpendicularly upon them, and 
merely press the arms against the building, per- 
pendicular to the plane in which they are de- 
signed to move. If, on the other hand, the sails 
were perpendicular to the plane in which the 
arms move, their edges would be presented to 
the wind, and would, therefore, offer no resist- 
Dee 
