Page:Dick Sands the Boy Captain.djvu/143

 ROUGH WEATHER. I17 wîU ensue; and the longer the time between the first rising of the mercury and the commencement of the fine weather, the longer the fine weather may be expected to last 3. If îmmediately after the fall or rîse of the mercury a change of weather ensues, the change will be of no long continuance/ 4. A graduai rîse for two or three days durîng raîn forecasts fine weather ; but if there be a fall immediately on the arrivai of the fine weather, it will not be for long. This rule holds also conversely. 5. In spring and autumn a sudden fall indicates rain ; in the summer, if very hot, it foretells a storm. In the winter, * after a period of steady frost, a fall prognostîcates a change of wind with rain and hail ; whilst a rîse announces the approach of snow. 6. Rapîd oscillations of the mercury either way are not to be interpreted as indicating either wet or dry weather of any duration ; continuance of either fair or foui weather is forecast only by a prolonged and steady rise or fall beforehand. 7. At the end of autumn, after a period of wind and rain, a rise may be expected to be foUowed by north wind and frost. Not merely had Dick got thèse rules by rote, but he had tested them by his own observations, and had become sing^larly trustworthy in his forecasts of the weather. He made a point of consultîng the barometer several times every day, and although to ail appearances the sky indicated that the fine weather was settled, it did not escape his observation that on the 20th the mercury showed a tendency to fall. Dick knew that rain, if it came, would be accompanied by wind ; an opinion in which he was very soon confirmed by the breeze freshening, till the air was displaced at the rate of nearly sixty feet a second, or more ' This and several of the other raies are concisely concentrated in the couplet— Longforetold, hnglasl ; SÂort notice^ so<m past.