Page:Polar Exploration - Bruce - 1911.djvu/211

Rh at sea—was a very good one, as the gauge was never sheltered by the sails. The thickness of the rainband in the spectrum of sunlight was taken daily at noon, and the temperature of the sea surface was observed every four hours, and at more frequent intervals when rapid changes were in progress.

For ascertaining rapid fluctuations of the atmospheric pressure a Richard statoscope was employed; this is really an extremely delicate recording aneroid, in which changes of pressure are magnified twenty-five times. This instrument was also used for recording the height of waves. A chart put into motion by clockwork receives a trace of the pressure-fluctuations due to the rise and fall of the waves, the height of which could thus be calculated. Attempts were also made to fly kites for recording meteorological observations at high altitudes, but it was found difficult to get the kite clear away from the ship owing to eddies formed by the heavy masts, yards and rigging of a full-barque-rigged ship, although several of us were quite proficient in getting kites clear away from a small steamer which had less heavy rigging. Another drawback was that the speed of the Scotia was scarcely sufficient under some conditions to keep the kites flying well. It may be noted that Mr. John Anderson, the pioneer of meteorological kite-work in Scotland, had