The ancient Greek philosophers
and mathematicians gathered students 
around
them, or schools, to expound their thoughts, who might then go on to
develop their own schools or they would stay with the master to build
an enclave or society. Sometimes surrounded with secrecy or scandal.
Example Pythagoras or Socrates or Plato etc..
With the invention of the
printing press in the 15th century, individuals would "publish"
their writings, and now have multiple copies distributed to an international
audience. Making its debut in 1665, the first "journal" to
be published was the French "Journal des scavans", devoted
to the discourse on intellectual subjects. Primarily it published book
reviews, but occasionally included observations and experiments. A few
months later, the recording secretary of the English Royal Society,
began publishing the Philosophical Transactions which included some
of the international correspondence (letters) describing experiments,
observations, natural wonders, instrumentation, and mathematical innovations
