How did the earliest scientists pass information on withe out pen or paper?

Many useful facts were early passd on by Word of mouth. Pre-literate peoples such as the Polynesians, had very extensive knowledge of the pattern of stars, and of seasonal migrations of birds. In fact, in recent years, some navigation using traditional methods was proven to be not inferior over Pacific distances.

And of course, even in quite primitive societies, the ability to count is a taught culture.