The inventor of Morse code, Samuel Morse (1791-1872), needed to know this so that he could give the simplest codes to the most frequently used letters. He did it simply by counting the number of letters in sets of printers' type. The figures he came up with were:
12,000 E 2,500 F
9,000 T 2,000 W, Y
8,000 A, I, N, O, S
1,700 G, P
6,400 H 1,600 B
6,200 R 1,200 V
4,400 D 800 K
4,000 L 500 Q
3,400 U 400 J, X
3,000 C, M 200 Z
Read the full story at:
http://www.oxforddictionaries.com/us/words/which-letters-are-used-most
Image from:
http://www.officemuseum.com/Telegraph_key.jpg
