> James Landau remarks:
>
>> A few months ago, as part of the thread "Early Mathematics", we
>> discussed the history of base 5 versus base 10. Now it seems that
>> we're into base 20.
>
> There's also base 4. The following is from a beautiful book by Sturmius.
Johann Christophorus Sturm (1635-1703)
> My copy was published in London in 1700. I don't know when Sturmius first
> wrote it, but he was at Altdorf, and this is a translation (translated by
> J.R.,
The British Museum Catalogue suggests that the translator might be a certain
J. Rogers. However, other catalogues suggest that "J.R." was the British
mathematician Joseph Ra(l)phson.
> A.M. and R.S.S. I wonder who they were?), so surely it was written
> before 1700.
It was first published in 1689. A second edition (also in Latin) appeared
in 1695.
> The title page includes the following:
>
> Mathesis Enucleata:
> Or, the
> Elements
> Of the
> Mathematicks
> By J. Christ. Sturmius
> [...]
> 1700
>
Incidentally, Florian Cajori remarks that
Perhaps the earliest use of a single letter to represent
the ratio of the length of a circle to its diameter occurs
in a work of J. Chr. Sturm (*), professor at the University
of Altdorf in Babaria, who in 1869 used the letter $e$ in
a statement, "si diameter alicuius circuli ponatur $a$,
circumferentiam appellari posse $ea$ (quaecumque enim inter
eas fuerit ratio, illius nomen potest designari littera $e$)."
Sturm's letter failed of general adoption.
(*) J. Christoph Sturm, _Mathesis enucleata_ (Nu"rnberg, 1689), p. 81.
This reference is taken from A. Krazer's note in _Euleri opera omnia_
(1st ser.), Vol. VIII, p. 134.
Best regards,
Julio Gonzalez Cabillon