I might be wrong, but I believe they were handwritten in the submitted manuscripts then manually typeset by the publisher. In Feynman's PhD thesis, all of the

I might be wrong, but I believe they were handwritten in the submitted manuscripts then manually typeset by the publisher. In Feynman's PhD thesis, all of the formulae are written in: http://cds.cern.ch/record/101498/files/Thesis-1942-Feynman.pdf http://cds.cern.ch/record/101498/files/Thesis-1942-Feynman.p...