...top of tube between inner and outer surface in capillary...
This is just an idea, but perhaps formula 1) came from this derivation, putting the up and downward forces equal πr2hρg=Tcosθ2πr(2)(2)πr2hρg=Tcosθ2πr where the left rr will later be replaced with aa and the right rr replaced with bb, alth...