An Improved Brick or Block for use in Filter, Bacteria and like Beds where Sewage or Impure Water is Treated.

摘要

1873. Lonsdale, J. Jan. 28. Flooring-bricks.-A brick for the drainage floors of filter beds, bacteria beds, &c. is formed with downwardly-directed channels a1, b1 at the ends and sides, communicating with transverse and longitudinal channels along the base.