From: Andrea Celli
Email: a.celli@infinito.it


The research institute where i work owns a differentio-integraph. I know only it was built by Askania-Werke (a german industry famous for optical and aereonautical instruments) just before II WW. We get if from italian Air Force at the end of the war, but it's a long history ...;-) Now, all documentation is missed. The only usefull reference I found is F.A. Willers, "Mathematische Maschinen und Instrumente" (1951) who says it was designed by von Harbou in 1930 adding a differential feature to classical Abdank's integraph. Now I'm interested in finding any kind of informations about it. bye, andrea Obviously I cannot and don't want sell it!!