Effect of Magnetism on Time-Pieces

1869 Scientific American  
82 J dtntifi' �tUttitatt. this system was carried out, in sinking seventy cylinders to a ! and the white man who comes within their reach is snapped great depth in the bed of a strong tidal river like the Med-! at in an instant by a score of ravenous mouths. But, strange way. The bed of the river was found to consist of strata of ! to say, a dark-skinned Polynesian will swim about in their soft clay, sand, and gravel over the chalk, which was reached i midst and rarely be molested. I have seen
more » ... ested. I have seen a native of the at a depth of 44 feet below average water line. Each cylin-I Hawaiian Islands fearlessly jump from the bow of a ship into der was like an immense diving bell, al ways having its top t the midst of a " school" of these fellows, swim, with the end of out of the water, no matter at what depth the bottom was. ' a line in his mouth, to one of the buoys, and return to the They are formed of cast-iron pipes,\) feet long and 7 feet di-vessel uninjured. ameter, with internal flanges, so that the external faces are Whether there is a sort of freemasonry between the sharks free of any projections that would interfere with their free I and the Kanakas, or whether the tastes of the shark are too descent t�ro � gh the be� of t�e riv � r. The accesr to and I fastidious, and not sufficiently cannibal to relish cannibal from the mSIde of the pIle, whIle bemg sunk, was through flesh, has not been satisfactorily explained. But the shark two air-locks or chambers, made of cast iron, passing through I and the Kanaka are on the friendliest terms imaginable. the cover-plate bolted on the top length of the pipe forming The flying fish abounds in these waters. When pursued the pile. The tops of these locks had openings 2 feet in di-by the dolphin, their foe, whole schools of them may frequent ameter, and flap-doors which, when closed, allowed them to ly be seen to leap out of the water and fly for several hundred be filled with the compressed air from the cylinders. From yards, skimming along quite near the surface, and now and each air-lock there was a vertical door opening into the airthen gaining new velocity by striking the crest of a wave chamber, which, when closed, was also air-tight, so that when with their long, ray-like, pectoral fins. But this beautiful the workmen had to pass in or out, or to take out the excafish h8,s enemies in the air as well as in the sea, and frequent vated material, they could do so without decreasing the ly its aerial flight is cut short by some fleet sea bird that is pressure of the air very much. In coming out, they entered, ever on the alert to seize its prey. through one of the vertical doors, into onQ or the other of the air-locks, and when this door was closed, the pressure of the air was reduced to atmospheric pressure by means of a small cock, opened to the atmosphere. As soon as there was
doi:10.1038/scientificamerican08071869-82a fatcat:gg6kri5c6rhjlpcsh4p4nfovmm