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