 | Henry Smith Williams - Inventions - 1913 - 392 pages
...Canal Zone by either raising the houses three feet from the ground on supports of concrete or other material, covered with tin, so that the rats cannot secure a footing on them. If placed on the ground they must rest on a floor of concrete. The buildings are submitted to inspection... | |
 | 1911 - 878 pages
...Canal zone by either raising the houses three feet from the ground on supports of concrete or other material, covered with tin, so that the rats cannot...the ground they must rest on a floor of concrete. The buildings are submitted to inspection at regular intervals; those not in a sanitary condition in... | |
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This is accomplished in the Canal zone by either raising the houses three feet from the ground on supports of concrete or other material, covered with tin, so that the rats cannot secure a footing on them, or if placed on the ground they must rest on... 