On the Effect of the Free Surface upon the Virtual Mass of Submerged Bodies and Ships

In this paper, the author investigated into the effect of the free surface of water upon the virtual mass of submerged solids moving parallel to the free surface, and obtained following results:1) The virtual mass of solid decreases by the effect of the free surface.2) The virtual mass is not effected by the velocity of the solid, and is always constant when the depth of the solid is constant.3) The effect of the free surface is represented by the effect of a solid placed at the image point of the submerged solid against the free surface, and has negative velocity.