Chichester A Bell, American sound engineer, late 19th century.

Crosley table telephone, 1879.

Crosley table telephone, 1879.

Portable telephone.

Portable telephone.

Portable telephone with large battery pack,

Portable telephone with large battery pack,

Elizabeth Bell, mother of Alexander Graham Bell, c 1840s.

Bell's liquid transmitter, March 1876.

Silvanus P Thompson's 'valve' telephone, 1882-85.

Gower-Bell telephone, 1881.

Gower-Bell telephone, 1881.