| 1930 FRANK Electric Signal Bell Patent Print Art |
| 1930 ELECTRIC SIGNAL LTD Signal Art Print |
| 1921 BAGNELL Electric Signal Switch Patent Print |
| 1938 GAYNOR Audible Electric Signal Patent Print |
| 1924 WARREN Electric Signal Device Patent Print |
| 1935 SCHWARZE ELECTRIC Audible Signal Art Print |
| 1933 HOLTZER CABOT ELECTRIC Signal Art Print |
| 1930 ANTHONY Electric Signal Switch Art Print |
| 1938 SCHWARZE ELECTRIC Chime Signal Art Print |
| 1929 THOMAS Electric Signal System Patent Print |
| 1932 ANTHONY Electric Signal Switch Art Print |
| 1936 CARL Audible Electric Signal Patent Print |
| 1925 NORTH EAST ELECTRIC Signal Horn Art Print |
| 1951 JOHN Electric Signal Switch Patent Print |
| 1921 HAZAZER EDGAR Electric Signal Patent Print |
| 1936 SIGNOR Electric Flare Signal Patent Print |
| 1960 SMITH Electric Signal Device Patent Print |
| 1937 GEN ELECTRIC Signal System Patent Print Art |
| 1924 SCHIRMER CYRUS Electric Signal Patent Print |
| 1931 CHEATHAM Electric Signal System Art Print |