Yes this article is about this photo of Richard Dedekind…

I happen to see this photo on the newly updated English Wikipedia page of Richard Dedekind. It was uploaded by the library of ETH Zürich (A big thank you!). Apparently Dedekind was young when the photo was taken, so it could probably belong to his Zürich time (1858-1862), or some time around that. This was also the time when he carried out his 7-hour calculus lectures. The lecture notes taken by the students were later summarized into a book.

Notes of Dedekind’s lectures on calculus when he was professor at Zürich.

The caption on the Wikipedia page below the photo is quite misleading: “c. 1886” is definitely an inaccurate estimation of the time the photo was taken, since in 1886 Dedekind was already 55. Actually, a statement on the detailed information page of this photo says “before 1886″, because this is the year when the photographer, Johannes Ganz (1821-1886), died.

This photo is the first full-length portrait of Dedekind that I know so far, probably also the only existing one apart from the group photo of his bowling friends (see below). Will be very glad if there are others!!!

The Braunschweig professors going for bowling, among them Richard Dedekind. Source: TU Braunschweig.

If the table is 80 cm tall as a usual table, then Dedekind’s height is about 170 cm.

Not particularly tall, but a mathematical giant indeed. I am currently amazed by his theory of field automorphism (called permutations then) all the time!

I’m not really sure what it is in his hand. For me it is too small for a mathematical book, so could it be a Bible or a pocket notebook?

By the way, I will try to edit the Wikipedia page after my experiment module which ends this Wednesday. There are a few inaccuracies and I definitely have something to add.