Interprettion of Meteorological Records

Abstract

IN the interesting discussion of the records of Lander and Smith's instruments at Canterbury (NATURE, March 15) both Dr. Aitken (pp. 485, 534) and Mr. Omond (p. 512) appear to have overlooked the fact that no rain fell, but only snow to the depth of more than 1 inch. This snow was mixed with a little hail at the commencement of the storm, but no rain fell as assumed by both your correspondents. The records state that the 0. 26 inch of rainfall consisted of snow melted as it fell. The first sign of the storm was distant thunder and a darkening of the sky in the north-west. The glycerin barometer commenced its usual sharp rise before the first hail arrived and the storm was directly overhead. It is a curious fact that the rain or snow with a thunderstorm occurs with the sharp barometric rise, and not with the fall as one might expect. I think the great fall in temperature was due to the snow, and not as described by your correspondents. The rainfall curve did not begin first as suggested by Dr. Aitken, but the barometer as explained above. It is another curious fact that, although my house is the highest here, and has my anemometer on top of 30 feet of iron tubing above roof, and wireless telegraphy aërial 80 feet above street (with which I was busy at time of storm), yet no damage was done; but within mo yards much lower houses had chimneys and walls thrown down and roofs split, &c., and people were seriously injured. Many houses, windmills, and a church in the district were set on fire.