Slide rules

Alro Muiderkring small

AL-RO was a company founded in the 1930 by Ir C.J. Dussel & A. Pasveer. Their uniqueness of the circular slide rules was the metal case, which not only protected the metal case, but also acted as a stand for desktp use. At the end of the 1950s the company stopped producing the circular slide rules.

The Oughtred  Society made a special article about these circular slide rules in 2006.

The Alro Muiderkring  was made around 1963 and has electronic scales, mostly for radio frequency purposes.  The diameter is 6cm. The metal is aluminium.

This item  is in a fair to good condition, but the plastic has a tear , and comes with the leatherlike cover.

If you want pictures in a better resolution, don't hesitate to email me.