Translucent building blocks

摘要

A hollow building block of transparent material comprises four perpendicular walls defining a rectangle, and a partition wall extending obliquely with respect to a plane at right angles to said perpendicular walls, said partition wall forming a boundary of a hollow space within said building block for containing liquid and the arrangement being such that when said hollow space is partially filled with a transparent liquid, light incident upon one of said perpendicular walls of the block can be reflected through said block by total internal reflection at a portion of said oblique wall immersed in said liquid.