“ Irrespective of any scientific object, how much utility is there to all classes in what is commonly called 'weather wisdom'? In our variable climate, with a maritime population, numbers of small vessels, and especially fishing boats, how much life and property is risked unnecessarily by every unforeseen storm? Even animals, birds, and insects have a presaging instinct, perhaps a bodily feeling, that warns them; but man often neglects his perceptive and reasoning powers ”

“ Agriculturists, it is true, use weather-glasses: the sportsman knows their value for indicating a good or bad scenting day; but the coasting vessel puts to sea, the Shetland fisherman casts his nets, without the benefit of such a monitor, and perhaps without the weather wisdom which only a few possess, and cannot transfer to others. ”

“ Misty clouds forming, or hanging on heights, show wind and rain coming—if they remain, or descend. If they rise, or disperse, the weather will improve, or become fine.
When sea birds fly out early, and far to seaward, 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. As many creatures, besides birds, are affected by the approach of rain or wind, such indications should not be slighted by the observer of weather. ”

“ Taking the state of the barometer in connexion with the appearance of the weather one could make a satisfactory conclusion as to the quarter from which any violent wind would come. And the barometer, after very little practice, can be used by any man. There is no difficulty in using it sufficiently to know that danger is coming on; and if danger is coming on, a man refrains, of course, from exposing himself to it; the quarter from which the wind comes being of minor consequence. ”

“ A "high dawn" is when the first indications of daylight are seen above a bank of clouds. A "low dawn" is when the day breaks on or near the horizon. The first streaks of light being very low.
[20] Indications of weather, afforded by colours, seem to deserve more critical study than has been often given to the subject. Why a rosy hue at sunset, or a grey neutral tint at that time, should presage the reverse or their indications at sunrise;—why bright yellow should foretell wind at either time, and pale yellow, wet;—why clouds seem soft, like water colour ”

“ To find the index correction for a land barometer, comparison with a Standard at any part of the scale at which the mercury may happen to be, is generally considered sufficient. To test the marine barometer is a work of much more time, since it is necessary to find the correction for scale readings at about each half inch throughout the range of atmospheric pressure to which it may be exposed; and it becomes necessary to have recourse to artificial means of changing the pressure of the atmosphere on the surface of the mercury in the cistern. ”

“ No bad weather ever comes on our coasts without timely warning being given by the barometer. The oldest seaman are often deceived by the look of the weather, but there is no instance on record of very bad weather, such as would have involved loss of life to the extent we have heard of in several years, having come on without the barometer having given timely warning. ”

“ Difficult as it is to foretell weather accurately, much useful foresight may be acquired by combining the indications of instruments (such as the barometer, thermometer, and hygrometer) with atmospheric [6] appearances. What is more varying than the aspect of the sky? Colour, tint of clouds, their soft or hard look, their outline, size, height, direction, all vary rapidly, yet each is significant. ”

“ The veering of the winds is a direct consequence of the earth's rotation, while currents of air from the polar regions are alternating or contending with others from the equator.
The polar currents are cold, dry, and heavy. Those from the equatorial parts of the world are warm, moist, and comparatively light. Their alternate or combined action, with the agencies of solar heat and electricity, cause the varieties of weather that we experience. ”

“ Familiar as the practical use of weather-glasses is, at sea as well as on land, only those who have long watched their indications, and compared them carefully, are really able to conclude more than that the rising glass [3] USUALLY foretells less wind or rain, a falling barometer more rain or wind, or both; a high one fine weather, and a low, the contrary. ”

“ Some whirlwinds are accompanied by rushes from the upper atmosphere, from the colder regions, which, mingling with warmer and moister air near the sea, cause dense clouds. About their centre it sometimes happens that the barometer falls as much as two or three inches, showing a diminution of atmospheric pressure by nearly a tenth part; when it should be expected, from physical considerations alone, that very dense clouds would be formed. ”

“ Thunder clouds sometimes rise and spread against the wind (lower-current) . It is probable that there is a meeting, if not a contest of air currents, electrically different, whenever lightning is seen. Their concurrence, when the new one advances from polar regions, does not depress the barometer, except in oscillations of the mercury, which are very remarkable at some such times. ”

“ Not only are reliable weather-glasses required at the smaller outlying ports and fishing places, but plain, easily intelligible directions for using them should be accessible to the seafaring population, so that the masters of small vessels, and fishermen, might be forewarned of coming changes in time to prepare for them, and thus become instrumental in saving much property and many lives. ”

“ 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 more rain) may be expected;—and the harder, more "greasy," rolled, tufted, or ragged, the stronger the coming wind will prove. Also, a bright yellow sky at sunset presages wind ”

“ When the barometer is rather below its ordinary height, say, below twenty-nine inches and nine-tenths (at the sea level only) , a rise foretells less wind, or a change in its direction towards the Northward,—or less wet; but when the mercury [12] has been low, say near 29 inches—the first rising usually precedes, and foretells, strong wind— (at times heavy squalls) —from the North-westward—Northward—or North-eastward—after which violence a rising glass foretells improving weather—if the thermometer falls. ”

“ Such a pressure holds the limpet to the rock when, by contracting itself, the fish has made a place without air [6] under its shell. Another familiar instance is that of the fly which walks on the ceiling with feet that stick. The barometer tube, emptied of air, and filled with pure mercury, is turned [8] down into a cup or cistern containing the same fluid, which, feeling the weight of air, is so pressed by it as to balance a column of about thirty inches (more or less) in the tube, where no air presses on the top of the column. ”

“ The barometer is said to be falling when the mercury in the tube is sinking, at which time its upper surface is sometimes concave or hollow. The barometer is rising when the mercurial column is lengthening; its upper surface being then, as in general, convex or rounded. [14]
A rapid rise of the barometer indicates unsettled weather. A slow rise, or steadiness, with dryness, shows fair weather.
A considerable and rapid fall is a sign of stormy weather and rain. Alternate rising and sinking show very unsettled weather. ”

“ A squall cloud that can be seen through or under is not likely to bring, or be accompanied by, so much wind as a dark continued cloud extending beyond the horizon. How the comparative hardness or softness of clouds foretells more or less wind or rain, was stated in pages 13 and 14. ”

“ In the trade winds of the tropics there is usually a counter current of air, with light clouds,—which does not indicate any approaching change. In middle latitudes such upper currents are not so evident, except before a change of weather.
[22] Much refraction is a sign of Easterly wind. Remarkable clearness is a bad sign. ”

“ Such considerations show in some degree why the barometric changes usually precede, but sometimes only accompany, changes of weather: and, though very rarely, occur without any sensible alteration in the wind current of the atmosphere. An observer may be near a central point towards which the surrounding fluid tends,—or from which it diverges. He may be at the very farthest limit of the portion of fluid that is so influenced. He may be at an intermediate point—or he may be between bodies of atmosphere tending towards opposite directions. ”

“ But the bulb of the tube is [9] full of mercury, which contracts by cold, and swells by heat—according to which effect the thread of metal in the small tube is drawn down or pushed up so many degrees: and thus shows the temperature. [8]
If a thermometer have a piece of linen tied round the bulb, wetted enough to keep it damp by a thread or wick dipping into a cup of water, it will show less heat than a dry one, in proportion to the dryness of the air, and quickness of drying. [9] In very damp weather, with or before rain, fog, or dew, two such thermometers will be nearly alike. ”

“ An observer may be under the centre of such accumulation or depression, he may be more or less distant from it, though within the influence of whatever horizontal movement of air may be caused by such temporary increase or diminution of pressure. Hence the barometer shows, and generally foretells, changes of wind ”

“ There is a peculiar aspect of the clouds before and during westerly winds which differs from that which they have previous to and during easterly winds, which is one only of the many curious facts connected with the differing natures of easterly and westerly currents of air throughout the world, which remain unchanged, whether they blow from sea to land, or the reverse. ”

“ For example: ten spaces on the vernier being made equal to nine on the scale, each vernier space is one tenth less than a scale space; and if the first line or division of the vernier agree exactly with any line of the scale, the next line of the vernier must be one tenth of a tenth (or one hundredth) of an inch from agreement with the next scale division ”

“ To render these pages rather more useful at sea, in any part [19] of the world, a few words about squalls and hurricanes are here offered to the young seaman.
Generally, squalls are preceded, or accompanied, or followed by clouds; but the very dangerous "white squall" (of the West Indies and other regions) , is indicated only by a rushing sound, and by white wave crests.
"Descending squalls" come slanting downwards, off high land, [27] or from upper regions of atmosphere. They are dangerous, being sometimes violently strong. ”

“ The vernier of a barometer reading to thousandths of an inch, is on a similar principle, though differently divided. In this application of it, generally, twenty-five vernier spaces equal twenty-four of the scale spaces, which are each half a tenth, or five hundredths of an inch ”

“ The gas in the box, changing it bulk on a change of temperature, was intended to compensate for the effect on the metals of which the aneroid is made. Besides which, a further and more, reliable compensation has lately been effected by a combination of brass and steel bars. [35]
[23]
Metallic barometers (in outer shape and size like aneroids) have not yet been tested adequately in very moist, hot, or cold air for a sufficient time. They, as well as sympiesometers, are likewise dependent or secondary instruments, and liable to deterioration. ”

“ By the very small expense of an establishment of barometers, so placed as to be accessible to any fishermen, boatmen, or others on the coasts, much loss of life, as well as loss of boats, and even shipping, might be prevented. ”

“ It stands lower, about a tenth of an inch for each hundred feet of height directly upwards, or vertically, above the sea; where its average height, in England, is 29·94 inches (at 32°) .
[12] In an Aneroid, a metallic, or a wheel barometer, the hand's motion should correspond to that of mercury in an independent instrument. ”