Show p hollow bricks popular during the past few years the use of hollow blocks and hollow bric bricks ks has extended rapidly these are much lighter than solid bricks and effect an important saving in railway carriage but they must be distinguished from porous bricks the weight alone Is not a sufficient guide as hollow bricks are now made which are in distinguish able in appearance from solid bricks when cut or broken their hollowness is easily seen on the continent por ous bricka bricks are defined as having a weight which Is notably less than common bricks but this definition will have to be abandoned now that hoi hot low bricks are made in large numbers |