So, what was the “new math” in 1810? Find out in NUMDAM (Numérisation de documents anciens mathématiques), a database of 50+ mathematical journals and seminars. The content is mostly French, but I am told there is English in there. Coverage runs from the 1800’s up to near Present (the most recent articles are only for subscribers). And if you have some relatively free time, you might want to look up Mr. A. Einstein’s “Théorie unitaire du champ physique” from 1930.
*CAUTION* Please do not try to view content with the DJVU links. Stick to .pdf for full text.