316 Ue of the Barometer as applied to Agriculture.[May

certained, the returns of rain or fair weather may be judged of with Some degree of certainty, in 80me gears, but Scarcely guessed at in others by means of the Barometer; for in ge- neral we may expect that when the mercury rises high, a few days of fair weather will follow. Ifthe mercury falls again in two or three days, but soon rises high, without much rain, we may expect fair weather for Several days; and in this case, the clearest days are after the mercury begins to fall,(contrary to the general expectation, perhaps.) dn the 3zame manver, if the mercury falls very Jow with much rain, rises Soon, but falls again in a day or two, with rain, a continuance of bad weather may be feared. If the Second fall does not bring much rain, but the. mercury rises gradually pretty high, it Prognosticates Settled good weather of Some continuance when a heavy rain has fallen upon the mercury's Sinking, and its continuing steadily low, the weather is Sometimes fair and Ppromises well; but no prudent farmer Should trust to Such ap- Pearances. There is, indeed; a caution, which every observer may profit by. When the mercury rises high in the barometer, the moisture on the surtace of the earth disappears; this, even though the sky be overcast, is a Sure Sign of fair weather; but if the earth continues moist and water Stands in Shallow places, no trust Should be put in tbe clearest ky, forit is in this case deceitful.

“« In the latter end of March, or generallyinthe beginning of April, the baroweter Sinks very low with bad weather,* after SBI it Seldom falls lower than 29 deg. 5 min. till the latter end'of September or October, when the quicksilver again falls low with Stormy winds, fer then the winter consfitution of the air takes place. From October to April the great falls of the barometer are from 29 deg. 5 min. to 28 deg. 5 min. and Some- times lower; whereas during the Summer constitutzon of the air, the„mercury Seldom falls Jower than 29 deg. 5 min. It therefore follows from hence, that-a fall of oze Zenrth of an inch during the Summer, is as Sure an indication of rain, as ä fall of between /wo and three lenths is in the winter.

“It must be observed that these heights ofthe barometer hold only in places pearly on a level with the Sea; for experiments have taught us-that for. every eighty ieet of nearly perpendi- cular height, the barometer is placed above the Jevel of the Sea, the quicksilver inks one tenth of an inch. Observatiou,

accuracy the approach of rain, At this moment the barometer standing stea» dily at 29 deg. 4 min. foretclls that the. bailey, yet un5o2un, is likely to re- main 80 for svöme time, unlcss other meons than«riding are resorted to 3 whereas the former part of this month has been peculiarly favourable to the Operations of the drill machine,

5 This year is certainly an CEXCEPtiON,

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