Product Number: 1920
20 in stock
The complete development of Early Experimental Ideas, Invention & Design from 1830-1930, starting with the old Military and Naval Signal Flags still in use today, each flag spells an alphabetic message, letter by letter. The next stage was the electric telegraph, the switching of electric current and needles, spelling out a letter-coded message. Finally, the speaking telephone, now the mini-computer: camera /smartphone we know today, with easy downloads.