Chamberlain's Improved Drawing Board
1849
Potential reducing board for charging accumulators by A. Gaiffe
1890-1910
Resistor, wooden board
1901-1930
Rheostat, on wood board with metal fittings
1801-1850
Open-spring rheostat, 1850-1910
1850-1910
Rheostat, wooden board and metal fittings
1901-1930
Micrometer microscope signed by M. Meyerstein
1831-1870
"CDX" X-ray machine
1923-1928