Fig. 17
Volcanic Winds: Due to volcanic eruption, which produces an outrush of air.
A Squall: Due to the sudden disturbance in temperature.
A Simoon: A desert wind.
VELOCITY OF WIND
The wind blows a great deal harder on water than on land, because on land it meets with various obstacles, whereas it has very little friction on the water.
THE FORCE OF THE WINDS
Wind blowing at 20 miles per hour has a force of 1¼ lbs.
Wind blowing at 35 miles per hour has a force of 6 lbs.
Wind blowing at 50 miles per hour has a force of 13 lbs.