Page:Scott's Last Expedition, Volume 1.djvu/516

336 gradually. One may well wonder how such a phenomenon is possible. In the middle of a period of placid calm and out of a clear sky there suddenly rushed upon one this volume of comparatively warm air; it has come and gone like the whirlwind.

Whence comes it and whither goeth?

Went round the bergs after lunch on ski—splendid surface and quite a good light.

We are now getting good records with the tide gauge after a great deal of trouble. Day has given much of his time to the matter, and after a good deal of discussion has pretty well mastered the principles. We brought a self-recording instrument from New Zealand, but this was passed over to Campbell. It has not been an easy matter to manufacture one for our own use. The wire from the bottom weight is led through a tube filled with paraffin as in Discovery days, and kept tight by a counter weight after passage through a block on a stanchion rising 6 feet above the floe.

In his first instrument Day arranged for this wire to pass around a pulley, the revolution of which actuated the pen of the recording drum. This should have been successful but for the difficulty of making good mechanical connection between the recorder and the pulley. Backlash caused an unreliable record, and this arrangement had to be abandoned. The motion of the wire was then made to actuate the recorder through a hinged lever, and this arrangement holds, but days and even weeks have been lost in grappling the difficulties of adjustment between the limits of the tide and those of the recording drum;