1 gen 1848 anni - System Palmer

Descrizione:

French inventor J. Palmer receives a patent for the ‘System Palmer’, the first micrometer still recognizable today with its U-shaped frame. Modern micrometers closely follow the System Palmer’s basic design of a U-shaped frame, thimble, sleeve, spindle, anvil, etc. Besides, all micrometers and other hand tools must still be traceable to the International Standard.