Thank goodness for people with weird hobbies. Arnold Betzwieser is a tax lawyer in Miltenberg, Germany. On the website for his law firm, alongside business info, he has a non-tax-matter-related section called "Small Exhibition: Interesting facts worth knowing about the historical development of office technology – when there were no computers."

At that latter link, I found this crazy "Architect's typewriter" from 1966, informally called a Gritzner:

Image: Arnold Betzwieser

Image: Arnold Betzwieser

Betzwieser explains:

"The 'Gritzner' was a typewriter specially developed for use on the drawing board, which was used in particular by architects, designers, technical draftsmen and similar professions for writing on blueprints and other technical drawings."

Image: Arnold Betzwieser

"The typewriter ran on a rail that could be moved like a ruler on the drafting table. Unlike normal typewriters, the "Gritzner" did not have a carriage, but wrote directly on the flat writing surface of the construction drawing in the upper lapel. The machine was therefore one of the 'flat typewriters'."

Image: Arnold Betzwieser

Image: Arnold Betzwieser

"With each keystroke, the machine moved one character width to the right on the rail above the paper. A long helical tension spring attached to the underside of the machine, attached to one long side of the rail and running via a deflection roller to the other side of the rail, served as the pulling mechanism (picture below)."

Image: Arnold Betzwieser

"There was no line break; the line was adjusted by moving the rail up or down."

Image: Arnold Betzwieser

Image: Arnold Betzwieser

I managed to find a vintage ad for the machine:

Betzwieser's website also has a section for jokes called "Smile Corner." Sample:

"If the employee dies during the business trip, the business trip is over." (Comment on the Federal Travel Expenses Act)

Ah, the German sense of humor.