I have a question about this gauge I picked up it
is marked Strong Minutes per feet and over the oval is Feet per minute
Made by Stewart Warner and has the same body and cable mounting as the 490
Might be vintage aircraft instrument? Planes use feet per minute calculations.
Now it's cable driven so not likely for air craft. Guess maybe for slow speed auto? Some one wanted to know ground speed in less than miles per hour. City taxi cabs are slow!
Automobile speedometers and odometers evolved from instruments used on looms, lathes and other machinery before there were cars. Warner was a successful company and then they started supplying the automotive trade.
Some trucks and electric cars had a speedometer that ranged all the way up to 30 MPH.
Look on the right end of this engine.
feet per minute is used for spraying equipment
Thank you everyone who posted I will clean it up a little look inside to see how it compares to the 490 Thanks Bill