Improvements in the Construction of Hollow or Tubular Building Tiles

15,960. Wie, E. E. van, and Jacob, J. J. July 21. Building-blocks for arches, columns, culverts, walls, &c. Longitudinal slots 2 are made in the tubes 1 for about half their length, and grooves 3 extend from the slots to the ends of the tubes. The grooved portions of the tubes slide in the slots of adjacent tubes, and the slotted ends may be tapered to fit in the non-slotted expanded ends or sockets of the adjacent tubes. The tubes may be made of artificial stone, terra-cotta, glass, metal, or other material.