Page:Popular Science Monthly Volume 90.djvu/115

 Popular Science Monthly

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��Salmon Fishing at the Mouth of the Columbia River

IF a fisherman has luck when seining for salmon, he generally gets a haul weigh- ing many tons. It is perhaps for this rea- son more than for any other that so many launches and seining-skiffs may be seen with their nets just inside the great promontory near the mouth of the Colum- bia River. For net-fishing for salmon — seining, as it is called — at this fruitful spot is nearly always very dangerous. Never- theless, in some seasons nearly five hundred tons of Chinook salmon — the most valuable and most prized fish of the species — are taken by a single crew. Individual hauls sometimes reach eighteen tons, and the record catch for one day has reached as high as fifty-two tons.

Because of the promontory on one side of the fishing-grounds and Sand Island lying directly opposite the river's mouth, the breakers constantly ride high. When the steamers of the Great Northern Pacific ply through the narrow grounds at a speed of twenty-three miles an hour, the breakers pushed out from their side pile so high that fishing is utterly impossible. If the launches and skiffs are caught too close in- shore to weather the breakers, there will be little chance for them to get to safety.

Certain conditions seem to be most favorable to the formation of high waves by the steamers. During an ebb tide and an off-shore wind, the water is piled into solid waves often six and eight feet high. The suction produced at the sides of the steam- ers is very great, and heavy nets are known to have been drawn in from a distance of two hundred feet and finally destroyed by the rapidly revolving pro- pellers of the ship.

����Salmon fishing at the mouth of the Columbia River is dan- gerous. Small skiffs and launches are often capsized and tiirown high and dry on the beach if not dashed to pieces

��The instrument used in making the coast surveys is a telescope mounted on a port- able tripod and having a delicate spirit level

Endangering Your Life for an Imaginary Line

FROM the mosquito-infested swamps of our lowlands to the highest peaks of our mountains and from the ice-locked northland of Alaska to the blistering sands of the tropics, the engineer in the service of the United States Coast and Geodetic Survey is facing privation and hardship for the sake of precision. He is laying a net- work of imaginary lines upon the maps of the States that we may know just how high a given place within the national boundaries is and in just what latitude and longitude it lies.

Thus, the surveyor in the accompanying photograph is establishing a line along a coast where it is necessary for him to stand in water up to his waist. He is obliged to work from this par- ticular spot because it enables him to see his observation point far away on the horizon. Otherwise he could not make his measurements and estab- lish his line.

However, he is taking fewer chances while he is working in the water than when he is establishing a line in a heavily wooded country. Where the land is flat and the trees of excessive height he sometimes has to work on giddy plat- forms more than a hundred feet above the ground.

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