An Act of Congress approved February 2, 1925, changed the rage of postage on
air mail carried on contract air mail routes to not less than 10 cents for each
ounce or fraction thereof.

"Contract air mail routes" meant that the U.S. Post Office Department was
issuing contracts for the movement of air mail, rather than taking on the task
itself.

The new rate provided for a charge of 10 cents per ounce for air mail sent
distances of up to 1,000 miles; 15 cents per ounce for distances between 1,000
and 1,500 miles; and, 20 cents per ounce for air mail sent distances greater
than 2,000 miles.