(13)

for liquid filling the cylinder; and

φ= th η,
φ1 th (η − α)

(14)

over the surface of η; so that parallel to Ox, the effective inertia of the cylinder η, displacing M′ liquid, is increased by M′th η/th(η- α), reducing when α = ∞ to M′ th η = M′ (b/a).

Similarly, parallel to Oy, the increase of effective inertia is M′/th η th (η − α), reducing to M′/th η = M′ (a/b), when α = ∞, and the liquid extends to infinity.

32. Next consider the motion given by

φ = m ch 2 (η − α) sin 2ξ, ψ = −m sh 2 (η − α) cos 2ξ;

(1)

in which ψ = 0 over the ellipse α, and