I had assumed it was empirical research. In other words you would have to had got yourself within range of a wet deer fart in order to observe and record its ballistics. Based on that data, one could move on to calculate the optimal length of the Stith tube. And we haven't even yet began to talk about field testing.

"The universal aptitude for ineptitude makes any human accomplishment an incredible miracle." John Stapp - "Stapp's Law"
"Klaatu barada nikto"