"BRADLEY'S, CUBE ROOT BLOCKS, No. 2, TO TWO PLACES", circa 1940? (wood box and 15 pieces, 3.25" square; pieces based on 1/2 unit cubes; two unit size cubes, one 3x3x3 cube, and three each of 1x1x3, 1x1x4, 1x3x3, 1x4x4)