ET in 1584

[Richard Moody]

>>>>>>>>>>>>
 In the equally tempered scale every semitone is 100 cents.
This temperament was devised by the Dutchman Simon Stevin, who
published his solution in 1584 !
<<<<<<<<<<<<<<<

The above I read on the Internet.  No reference was given as to the publication.
Has anyone else heard of this person and his work?  I would like to see how it
was actually "devised".   ---ric