Is it possible to calculate logarithms mechanically (other than with a slide rule)?

Question

I know that mechanical computers have been used for a number of different calculations, the most famous (at least on the internet) seems to be the firing control computer used by the US Navy. But were there any entirely mechanical devices (other than a slide rule) that could calculate logarithms?

Answer 1

Konrad Zuse developed the relais driven computer in 1942 in Berlin.

K. Zuse Z4 Computer

I got my qualification as an ALGOL programmer at U. Würzburg on a Zuse Z22 with electronic tubes in 1962.

K. Zuse Z22 Computer

Answer 2

Yes. The first was probably the Scheutz Difference Engine of 1855, who was inspired by Charles Babbage's uncompleted Difference Engine. There's also one by Martin Wiberg a decade or two later. You can read about a much later successful one on the Computer Timeline site:

The Differential Engine of Christel Hamann

In 1905 The Royal Prussian Academy of Sciences in Berlin placed a considerable sum (15000 Marks, later on Imperial Academy of Sciences in Vienna granted additional 8000 Krones) at the disposal of German professors Julius Bauschinger (Director of the Imperial Observatory of Strasbourg) and Johann Peters (assistant of the Royal Astronomical Calculating Institute of Berlin), in order to prepare and publish tables of logarithms to eight digital places of all numbers from 1 to 200000.

The work started using hand calculations in 1908, but the progress was so slow, that in the same year Bauschinger and Peters contacted Christel Hamann and asked him to put his long experience at his disposal and to construct a new machine, by means of which the values were to be reckoned from the second differences by summation and at once written down.

Hamann readily accepted the challenge. Only several months were enough for the genius-constructor, and the machine (see the nearby photo) was ready at the beginning of 1909. It immediately went into action, worked perfectly, and surpassed all expectations.

There were probably some others, but not very many since they are essentially very expensive single use machines. It is much more profitable to sell the logarithm tables they produce, or to construct a general mechanical calculator that can be sold many times.