Mechanical Pencil Month – Day 3: Nestler’s German silver screws
As promised, today's entry brings together Slide Rule Saturday and Mechanical Pencil Month in the hope of fostering a new spirit of love and cooperation between the two rival kingdoms.…
Sketchy calculation
As a bit of weekend fun, here's something called a Rechenstift - German for "calculating pen" - by the venerable Hamburg firm of Dennert & Pape, erstwhile inventors of the…