Logomat Pfiffikus 2001

The Pfiffikus 2001 is the smallest circular slide rule in my collection. It was produced in Germany in the early 19t0's to be a giveaway for customers purchasing other products. Fabricated with aluminum, a plastic movable cover with a hairline, and one transparent movable indicator, it is small enough to be be confounded with a key-chain, 1,94 inches (4.8 cm) diameter, but its simple 13.75 inches (32 cm) long spiral logarithmic scale makes this tiny rule fully functional to solve problems involving simple multiplications and divisions.

Calculations with this tiny rule require some practice, but it is a fun activity. In the picture below is compared with a US Quarter coin:

Here is a scan of the tiny user manual. It is in German but you can find in the link at the bottom of the page, a WEB version with English translation by Google:

Click on the next links to see professional panoramic pictures of the Pfiffikus 2001:

https://www.sliderulemuseum.com/HSRC/16511.jpgn

References:

• https://www.rechenwerkzeug.de/logomat.htm