ALEXANDER GRAHAM BELL PICTURES

GRAHAM BELL SPEAKING IN PROTOTYPE PHONE

BELL SPEAKING INTO PROTOTYPE TELEPHONE

Bell speaking into prototype telephone

1876 PHONE

ALEXANDER GRAHAM BELL USED THIS PHONE IN1876

GEAHAM BELL OPENING FIRST WIRE LINE ,IN 1892

Alexander Graham Bell at the opening of the long-distance line from New York to Chicago, 1892.

Alexander Graham Bell's Telephone

Alexander Graham Bell constructed this prototype telephone in 1875. The device consists of a coil of wire, a magnetic arm and a taut membrane. Any sound causes the membrane, and hence the magnetic arm, to vibrate. The movement of the magnet induces a fluctuating electric current in the coil. This electrical signal can be reconverted into sound by an identical apparatus at the other end of the circuit.

GRAHAM BELL FIRST PHONE PICTURE

ALEXANDER GRAHAM BELL PICTURE IN 1876