Monday, December 7, 2015

Aristo Nr. 99

A more modern sliderule made in 'Astrolon' plastic (polyvinylchloride). According to the numbers 471 on the back it was made in 1947 in batch 1 by Aristo (Dennert & Pape). A regular 10 inch 'system Rietz' sliderule.

Unlike later extruded models, this is milled from sheet material. Very straight and solid stock.

Glass window cursor with (circle area) C factor and kW to horsepower factors.

Have had this one since probably the mid eighties - have some memory of buying for 50 cents at a jumble sale. They'd only just been made properly obsolete then, so would have been ending up at the back of drawers. Or at jumble-sales :)

Pretty much a common, standard 'Rietz' sliderule that is surprisingly heavy and solid - feels 'precise'.


  1. I've enjoyed your sliderule collection. I used to have a circular sliderule.

    1. :-)
      Actually never used a circular. They're impressive bits of human ingenuity!

  2. Have slide with Dennert & Pape, Hamburg-Altona. System rietz.On end it has d & p circle symbol over Aristotle Nr 99 k. On back is 448. Box has stamp label with 4 April 1945 also with red d & p symbol. Also German Joe Klawun label. Can make sense of this for me? Thank you.

    1. Well that would be batch 8 of 1944, made commercially for Messinstitut Klawun of Berlin.
      Do have a look at the the excellent article by Hans Dennert at the Oughted Society; DENNERT & PAPE and ARISTO Slide Rules 1872 - 1978