Note 3 — Chapter VIII · BALLOONS.

Haswell gives the pressure of the wind at 40 miles an hour as 8 lbs. per square foot, and this is said to have been verified by the United States Coast Survey. Molesworth makes it slightly less; but the new formula, according to most recent experiments (Dr. Stanton’s experiments at the National Physical Laboratory and M. Eiffel’s at Eiffel Tower), is P = 0·003 V², which would make the pressure only 4·8 lbs. per square foot, and which would reduce the total H.P. required from 472 to 283, where P represents pounds per square foot and V miles per hour.