What does N stand for in Thomas Bayes' publication “An Essay towards solving a Problem in the Doctrine of Chances”

For example, in Prop 1, the beginning of the second paragraph.

Suppose there be three such events, and which ever of them happens I am to receive N, and that the probability of the 1st, 2d, and 3d are respectively $$\frac{a}{N}$$,$$\frac{b}{N}$$,$$\frac{c}{N}$$.

What does 'N' mean here? Also, what is the meaning of the expression, 'I am to receive N'?

The essay can be found here: http://www.stat.ucla.edu/history/essay.pdf

• It looks like an old fashioned way of saying that N is the number of trials, what we get if we count “whichever of them happens”. – Richard Ambler Jan 1 at 10:54