13th July in history

The Hollywood Sign was officially dedicated in the hills above Hollywood, Los Angeles on this day in 1923.

Did you know that:

• The source of the Mississippi River was discovered by American geographer Henry Schoolcraft on this day in 1832
• Swedish-American inventor John Ericsson filed for a patent for his screw propeller design on this day in 1835
• Patents were first numbered on this day in 1836, changing the way the system of patents and trademarks was organized

// Compiled by Zoya Siddiqui