National Geographic : 1915 Aug
FLASHLIGHT PHOTOGRAPH OF ONE OF SEVERAL VARIETIES OF OPOSSUMS ENCOUNTERED IN THE CANAL ZONE The particular opossum shown is the commonest species, and by reason of its abundance and its omnivorous appetite it proved a serious obstacle to flashlight photography. Probably 75 per cent of the flashes fired were sprung by opossums, who found and fired the camera shortly after dusk, before better game was moving. were carefully screened and inspected and the employees supplied gratuitously with quinine. By isolating, in conven iently located hospitals, all suspected or infected cases there was no possible chance for an epidemic to get a foothold. LOSING SANITARY CONTROL Now that most of the government towns about the lake have been disman tled or occupied only by a few perma nent employees, it should be easier to in sure proper health conditions along the canal route were it not for several changes which if ignored may cause a reversion to the old conditions or worse. The change that has taken place since the lake filled up the lower Chagres Val ley and extended far inland, flooding temporarily, and at places permanently, lowlands far beyond the zone, has already been mentioned. Taking the lake as a whole, and after the stagnation caused by decaying vegetation has ceased, it ought to be sufficiently pure for many do mestic uses. Probably 90 per cent of the supply is the quickly delivered torrential rains, and the remainder, mostly during the dry season, is the contribution of small streams fed by the stored waters of the limestone formations; so its purity nearly equals that of distilled water. With a depth in the main part surpass ing that of Lake Erie, the surface rough ened and aerated by daily winds and the rotting vegetation replaced by aquatic growths favorable to purification, there is no apparent reason why such water should not be piped, as now contemplated, to the cities of Panama and Colon or the neighboring towns, as well as becoming an important source of supply for the numerous ships en route between distant ports.