 In building up the filtering-bed, provision is first made for the ready collection of the water by constructing upon the floor of the basin drains or channel-ways of stone or brick laid dry; then follows a layer of broken stone, the fragments being three...  Report [for the Year Ending Dec. 31]. - Página 301875Vista completa - Acerca de este libro
 | United States. War Department - 1880 - 760 páginas
...up the filtering beds, provision is first made for the ready collection of the water by constructing upon the floor of the basin drains or channel-ways...screened so as to be of uniform size ; a layer of coarser being followed by one or more layers of fine material; upon the gravel rests sand likewise... | |
 | United States. Army. Corps of Engineers - 1880 - 762 páginas
...np the filtering beds, provision is first made for the ready collection of the water by constructing upon the floor of the basin drains or channel-ways...diameter. This is succeeded by gravel screened so us to be of uniform size ; a layer of coarser being followed by one or more layers of line material;... | |
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