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CONCERNING DEEP SEA SOUNDING.
BY
Captain BELKNAP, U.S.N.
Read before the Asiatic Society of Japan,
on the 13th May, 1874.
——o——
The accurate determination of the depth of the sea is a problem which has long puzzled the minds of seamen and scientists, but which now seems in a fair way of satisfactory solution.
The activity of scientific research in all branches of investigation, and the needs of commerce at the present day, demanding quick intercourse between remote parts of the world by means of telegraphic communication through submarine cables, have stimulated effort in the direction of Deep Sea Sounding, and finally made easy and indisputable a work which had hitherto been difficult and unreliable.
We hear no longer of almost bottomless depths in the Ocean; of pressures so great that nothing, whether of wood or iron, could sink below their plane; of an utter absence of life on the Ocean bed; or of a uniform temperature of 39° F., which was believed to exist after reaching down to a certain point beneath the surface. All these ideas have been exploded by the invention of the needed appliances, and the results of Deep Sea work during the past twenty years.
Under old methods with ordinary sinkers and heavy hempen lines, it was found exceedingly difficult to tell when the lead reached bottom in depths beyond 1,200
