578 



METEOROLOGY. 



agency being yet uncertain) to affect the barom- 

 eter: 



1. The direction of the wind, the N". E. 

 wind tending to raise it most the S. "W. to 

 lower it most ; and wind from points of the 

 compass between these, in proportion, as they 

 are nearer one or the other extreme point. N. 

 E. and S. W. may therefore be called the 

 wind's extreme bearings (by some, its poles). 

 Other things being the same, the entire range 

 or difference of height of the barometer that 

 can occur through change of the wind only, 

 from one of these bearings to the other, 

 amounts in these latitudes to about half an 

 inch. 



2. The amount of vapor, moisture, rain, or 

 snow in the wind or current of air. Other 

 things being the same, this appears capable of 

 causing a change in an extreme case of about 

 half an inch. 



3. The strength or force of a wind (apart 

 from other conditions), coming from any quar- 

 ter. Other things being the same, the strength 

 of the wind, according as less or greater, is pre- 

 ceded or foretold by a fall or rise ranging in 

 an extreme case to more than two inches. 



Hence, supposing the three causes to act to- 

 gether, in extreme cases, the height of the ba- 

 rometer would vary from near 31 inches to 

 about 27 inches, before and during a given 

 change of weather; and this, though rarely, 

 has happened, and even in tropical latitudes. 

 In general, however, the three causes act much 

 less strongly and less in accord ; just as ordi- 

 nary varieties of weather occur much more fre- 

 quently than extreme changes. 



Weather Signs. Mr. Fitzroy's summing up 

 of the more marked " signs " of weather, use- 

 ful alike to the seaman, the farmer, and the 

 gardener, embraces the following indications : 



Whether clear or cloudy, a rosy sky at sun- 

 set presages fine weather; a red sky in the 

 morning, bad weather, or much wind (perhaps 

 with rain) ; a gray sky in the morning, fine 

 weather ; a high dawn (the first daylight being 

 seen above a bank of clouds), wind ; a low 

 dawn (the first light being low or in the hori- 

 zon), fair weather. 



Soft-looking or delicate clouds foretell fine 

 weather, with moderate or light breezes ; hard- 

 edged, oily-looking clouds, wind. A dark, 

 gloomy, blue sky, is windy ; but a light, bright 

 blue sky indicates fine weather. Generally, the 

 softer clouds look, the less wind (but, perhaps, 

 the more rain) may be expected ; and tlie 

 harder, more " greasy," rolled, tufted, or rag- 

 ged, the stronger the coming wind will prove. 

 A bright yellow sky, at sunset, presages wind ; 

 a pale yellow, wet. Thus, by the prevalence 

 of red, yellow, or gray tints, the coming weath- 

 er may be very nearly foretold; almost ex- 

 actly, indeed, if coupled with the aid of instru- 

 ments. 



Small, inky-looking clouds foretell rain ; light 

 scud-clouds driving across heavy masses of 

 higher cloud show wind and rain ; if alone, they 



may indicate wind only. High upper clouds 

 crossing the sun, moon, or stars, in a direction 

 different from that of the lower clouds or of the 

 wind felt below, usually foretell a change of 

 wind. 



After fine clear weather, the first signs in the 

 eky of a coming change are usually light streaks, 

 curls, wisps, or mottled patches of white, dis- 

 tant clouds (cirri and cirro-cumuli), which in- 

 crease, and are followed by an overcasting of 

 murky vapor (the stratus) that grows into 

 cloudiness (cumulo-stratus.) This appearance, 

 more or less oily or watery, as wind or rain 

 will prevail, is an infallible sign. Usually, the 

 higher and more distant such clouds seem to 

 be, the more gradual, but general, the coming 

 change of weather will prove. 



Light, delicate, quiet tints or colors, with 

 soft, undefined forms of clouds, indicate 

 and accompany fine weather ; but gaudy or un- 

 usual hues, with hard, definitely outlined clouds, 

 foretell rain, and probably strong wind. Misty 

 clouds forming or hanging on heights, in case 

 they remain, increase, or descend, show wind 

 and rain coming. If such clouds rise or dis- 

 perse, the weather will improve or become fine. 



When sea birds fly out early, and far to sea- 

 ward, moderate wind and fair weather may be 

 expected ; when they hang about the land, or 

 over it, sometimes flying inland, expect a strong 

 wind, with stormy weather. When birds of 

 long flight, rooks, swallows, or others, hang 

 about home, and fly up and down, or low, rain 

 or wind may be expected. Many other creatures 

 besides birds give indications by their actions 

 of approaching rain or wind. When animals 

 seek sheltered places, instead of spreading over 

 their usual range, and when pigs carry straw 

 to their sties, an unfavorable change may be 

 expected. [The frequent whistling of quails 

 in summer, and the flight and screaming of the 

 nighthawk early in the afternoon, are very 

 sure indications of the near approach of rain.] 



Remarkable clearness of atmosphere near 

 the horizon, distant objects, such as hills, un- 

 usually visible, or raised (by refraction), and 

 what is called a " good hearing day " sounds 

 being heard with unusual clearness, or to un- 

 usual distances are among the signs, usually, 

 of rain, sometimes, of wind. Much refraction 

 (mirage) indicates an easterly wind. When, 

 during a calm, smoke ascends with difficulty or 

 to but little height, or settles, an unfavorable 

 change is indicated. 



Dew is an indication of fine weather; so is 

 fog. [Not always : in this country, very heavy 

 dew or white frost, especially if repeated, is al- 

 most a sure presage of rain ; and fog may pre- 

 cede, or occur during, long rains.] Dew never, 

 and fog seldom, occurs under an overcast sky, 

 or when there is much wind. Fog is occasion- 

 ally rolled away by wind, but seldom or never 

 formed while it is blowing. More than usual 

 twinkling of the stars, indistinctness or apparent 

 multiplication of the moon's horns, haloes, 

 " wind-dogs " (fragments of rainbows, or de- 



