Friday, December 4, 2015

Dennert & Pape Mannheim

In a dark brown leather sleeve, a Mannheim sliderule made in 1908 by Dennert & Pape of Altona.

Made of mahogany with celluloid scales. A very complete Mannheim with A[B C]D scales and S, T and a mantissa L on the back of the slide. Some yellowing of course, but overall in decent condition. It has a metal plate at the back over its length to keep the two halves of the stock under tension.

The German patent number 126499 of 1901 for this construction is engraved on the inside well of the stock that also has a ruler extension. Engraved in the well are the small digits that indicate the year of manufacture - 08. This particular rule was made with both a cm and inch ruler and the extender in the well in inches. Likely made for export to England.

The D&P logo is stamped on the cursor; glass window, single line. One detail is still a bit of a mystery; the AB scales have an extra marking with a dot at around 1143. This could have been added later, but it looks very clean as if factory made. Not yet caught on to what that number is...

Over a century old; that would make it a proper antique! - nevertheless still works fine.

Anybody with any hints that would shed light on the marking for 1143 or thereabouts, please do share :)


  1. Beautiful! :D
    No idea what the mark's for, though.

    1. It is rather :D
      the wood is very dark by now, contrasts with the shiny cursor. The scales are very crisp too!
      That mark is really intriguing. (Can't have been put there to just confuse, play a joke on a later owner. Or can it... ;-)