While the cement is still wet, line up a strip of brick with the end of the tube and put it on the tube. Rotate the square tube so the edge being glued can slide down to the work surface. This ensures the
edge of the brick is  lined up exactly with the corner of the square. Press the brick along its length to ensure it lays flat against the tube. If you get any glue on the face of the brick DO NOT press with your fingers or you may leave finger print impressions.  Instead press with your finger nail or the handle of the hobby knife.