# What fonts or typefaces were commonly used in old (pre-1950) mathematics literature?

I recall reading some books in my university library which were published in the 1920s and 1930s, and am wondering about their fonts. They looked very nice, and I would like to find some. It seems Monotype Modern was one such font, but it somehow costs hundreds of dollars despite the fact that its creator has been dead for a century.

Are there open source versions of such classic mathematical fonts?

Hint: Some related information is given in Mathematical Typography by D.E. Knuth from 1979. He discusses aspects of the development of typography used in AMS Transactions from 1900 up to the late 1970s in order to introduce $$\TeX$$ and $$\mathrm{METAFONT}$$.