Strowger calling dial, 1906
1906
1906
1908
circa 1910
1909
1910
1910
1910
1910
1906
1934
1910
2000-100 BCE
1872 (original); 1909 (model)
1955; 1830
1906
1907
1990-96
1907
1910
1907
1908
1934
1705-1737
1903 (original); 1982 (model)
1772 (original); 1919 (model)
4000-2001 BCE
1909
1906
1909-1910
1930 (replica); 1834 (original)
1801-1892 (prepared); 1946 (element replaced)
1830 (original); 1967 (model)
1906
1910
1989-08
1908
1910
1909
1909
circa 1910
1730; 1967
1909
1972-3
2500 BCE
1909
1910
1908
1907
1970-1910
1910