Frank Keiper, 1911 Encyclopædia Britannica, Volume 28… (1911)
“ Others, however, maintaining that secrecy was the essential idea of voting by ballot, and that the form of the ballot was immaterial, worked on the idea of using a key and a counter for each candidate, the counter registering the successive impulses given to it by the key, the machine preventing the voter from giving the key more than one impulse, and preventing the voter from operating more keys than he is entitled to vote. The highest courts of four different American states have ruled that any form of voting machine that secured secrecy would be constitutional. ”
