The wind dropped last night, but at 4 A.M. suddenly sprang up from a dead calm to 30 miles an hour. Almost instantaneously, certainly within the space of one minute, there was a temperature rise of nine degrees. It is the most extraordinary and interesting example of a rise of temperature with a southerly wind that I can remember. It is certainly difficult to account for unless we imagine that during the calm the surface layer of cold air is extremely thin and that there is a steep inverted gradient. When the wind arose the sky overhead was clearer than I ever remember to have seen it, the constellations brilliant, and the Milky Way like a bright auroral streamer.
The wind has continued all day, making it unpleasant out of doors. I went for a walk over the land; it was dark, the rock very black, very little snow lying; old footprints in the soft, sandy soil were filled with snow, showing quite white on a black ground. Have been digging away at food statistics.
Simpson has just given us a discourse, in the ordinary lecture series, on his instruments. Having already described these instruments, there is little to comment upon; he is excellently lucid in his explanations.
As an analogy to the attempt to make a scientific observation when the condition under consideration is affected by the means employed, he rather quaintly cited the impossibility of discovering the length of trousers by bending over to see!
The following are the instruments described:
|The outside (bimetallic) thermograph.|
|The inside thermograph (alcohol)||Alcohol in spiral, small lead pipe – float vessel.|
|The electrically recording anemometer||Cam device with contact on wheel; slowing arrangement, inertia of wheel.|
|The Dynes anemometer||Parabola on immersed float.|
|The recording wind vane||Metallic pen.|
|The magnetometer||Horizontal force measured in two directions – vertical force in one – timing arrangement.|
|The high and low potential apparatus of the balloon thermograph||Spotting arrangement and difference, see ante.|
Simpson is admirable as a worker, admirable as a scientist, and admirable as a lecturer.