Page:Polar Exploration - Bruce - 1911.djvu/239

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MAGNETISM, AURORA, AND TIDES
235

"Such a conclusion is interesting, but it would not be right," Darwin wisely adds, "to attribute to it a high degree of probability, because there are elements of uncertainty on every side." Still it is one more of those intensely interesting Antarctic problems which emphasise how much need there is for further Polar exploration.

Tidal observations were taken on board the Scotia every half-hour from March 25th to November 23rd, 1903, when the ship was frozen in in Scotia Bay. The device adopted for recording the tides was a simple one. A heavy weight with an attached piece of sounding wire was lowered over the ship's side, through a hole in the ice-floe in which the Scotia was frozen, to the bottom, which was here 10 fathoms. This wire was led over a block suspended to a davit, and at the end of the wire, on board ship, a second lighter well-shaped weight with a horizontal base was attached, and was suspended in such a way that it rose and fell up and down the face of a wooden scale. The floe in which the Scotia was frozen moved with the tide, the height of which was thus shown by the position of the movable weight on the scale.