I'm taking a history of maths course, and at the beginning of the chapter on the 20th century, it states that there was more work published in the 20th century than all the previous centuries combined. I understand this might be totally due to the ease of publication near the end of the century, but the question I have is, how much communication did intellectuals (math, physics, philosophy, ect) have with each other in each century (100s,200s,300s,...,1700s,1800s)?
Can't talk of specifics but generally it was very hard for intellectuals to spread their ideas unless they lived in a major city or worked in a place of learning for a society. Ideas were mainly spread in person.
Probably the break point was the arrival of the printing press in Europe in the 15/16th century as it allowed ideas to be spread much quicker. Though you could say it wasn't until the 18th century that intellectuals really started organising to work stuff out.
I did some research on the calculus dispute and by the seventeenth century you see scholarly societies promoting new ideas and mathematicians corresponding extensively. It was not as big a scholarly community as today but it was very closely connected. In Britain the Royal Society was crucial as was the French Academy of Sciences.
Sources
Correspondence of Isaac Newton (Cambridge, 7 volumes, 1959-)