Mechanical Pencil Month – Day 5: Rotring ArtPencil sets
It's Monday and we all probably need a bit of cheering up, so today's post is completely free from obscure patents, overcomplicated mechanisms and wacky design features (unless you count…
Mechanical Pencil Month
While digging around in the Repertory of Arts for Brunel patents, I came across a familiar design from the early 19th century. Granted to civil engineer John Isaac Hawkins (inventor…
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…