Coal oil first used for illuminating purposes in 1836.
Looms introduced as a substitute for spinning wheels in 1776.
The velocity of a severe storm is 36 miles an hour; that of a hurricane, 80 miles an hour.
National ensign of the United States formally adopted by Congress in 1777.
A square acre is a trifle less than 209 feet each way.
Six hundred and forty acres make a square mile.
A "hand" (employed in measuring horses' height) is four inches.
A span is 10-7/8 inches.
Six hundred pounds make a barrel of rice.
One hundred and ninety-six pounds make a barrel of flour.