Page:Great Neapolitan Earthquake of 1857.djvu/191

Rh

Here $$\beta = D$$, the diameter of the cylinder, therefore

Assuming the thickness of the walls small, as before, and $$\gamma$$ being that side of the parallelopiped, which is the axis of inceptive rotation, therefore

Then, $$\beta = \gamma$$, and (Eq. XXVI.) becomes