Improved form of mechanical counter, late 19th century.
late 19th century
Mechanical counting device, c 1900.
circa 1900
Casagrande liquid-limit apparatus
Revolution Counter, with five discs
1858
Revolution Counter German electric induction type
Jaeger clock type revolution counter
Revolution Counter
Revolution counter, inscribed with numbers
1862
Combined Revolution counter and stop watch in case
Small Hand revolution Counter
German clock type revolution counter and indicator
Revolution Counter MkIV by Smith
Aircraft engine revolution counter.
German Revolution Counter by Dr. TL.Horn Leipzig
Sectioned Revolution Counter WD
Sectioned Revolution Counter MkV
German Revolution Counter
'TEL' German Revolution Counter
TEL' German revolution counter
Sectioned Revolution Counter MkIV a.(mechanical)
German Revolution Counter by Morell No. 81184
A revolution counter, marked Cary/London
Revolution Counter by Elliott No. 8454
revolution counter
1960
revolution counter
Revolution-counter measuring unit
Casagrande liquid-limit apparatus
1967