A mid 19th c. Jakob Kern in Aarau Water Current Meter – Waltmann Wheel or Mill

A mid 19th c. Jakob Kern in Aarau Water Current Meter – Waltmann Wheel or Mill


Great patina and preservation. Rare and complete engineering tool



Country of manufacture


Categories: Scientific, Surveying Instruments & Mining


Woltmann Wheel signed J.Kern AArau – 1850 circa

A great horizontal-axis water current meter that was based on the form described by Reinhard Woltmann, a German hydraulic engineer, in 1790, made by the famous maker Jakob Kern. The instrument retains about the 95% of the original lacquer finish with just a couple of oxide spots. Complete and in working order. It is stored inside its original mahogany case, with inner velvet lined sockets to hold the instrument in position. The case shows some age signs but is still strong. Working lock

Great and rare add to any collection

“Clemens Herschel opined in 1869 that “The best instrument to measure the velocity of the current at any point has generally been thought to be the so-called Woltmann wheel, or tachometer.” James B. Francis did not mention an instrument of this sort in the first (1855) edition of his Lowell Hydraulic Experiments, but in 1868 he noted that “Woltman’s mill, or tachometer, has been much used for this purpose, but to insure correct results, its application is one of much delicacy, and in our large channels would require much time.”

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IT Scienzantica


Based in Florence, Italy, I have been collecting antique scientific instruments for the last 10 years. Some years ago I decided to turn this passion into my job, so I opened my personal website to sell all over the world. Thanks to my experience I managed to gain my client's trust offering an accurate service and good quality items. I sell all kinds of scientific instruments, especially French and Italian drawing sets. For more info you can contact me via email - scienzantica@gmail.com

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