paper will be in the least affected by this process, but, on the contrary, will be improved. A Composition to render Wood Fire-proof. Glass made by heating sand with twice its weight of soda-ash or pearlash is soluble in boiling water, when finely powdered. Applied with a brush, it renders woodwork fire-proof, and when once dry is not affected by cold water. To Render Dresses Incombustible. Take of a solution of tungstate of soda, of a specific gravity 1.14, 100 parts; phosphate of soda, 3 parts. The articles are dipped in the solution, and allowed to dry before ironing. This solution keeps well, and is used in the Royal laundry. How to Act when the Clothes take Fire. Three persons out of 4 would rush right up to the burning individual, and begin to paw with their hands without any definite aim. It is useless to tell the victim to do this or that, or call for water. In fact, it is generally best to say not a word, but seize a blanket from a bed, or a cloak, or any woollen fabric-if none is at hand, take any woollen material-hold the corners as far apart as you can, stretch them out higher than your head, and, running boldly to the person, make a motion of clasping in the arms, most about the shoulders. This instantly smothers the fire, tioned liquid); if the part is only small, it will then rise quickly, and appear as if repainted. New Mode of Preserving Impressions in Sand, etc. A sheet of thin iron-plate was placed over the marks made, and supported by an iron stand, at a distance of about 14 inches from the surface of the ground; a quantity of lighted charcoal was then placed on the iron plate, which soon became red hot, and of course heated the spot over which it was placed. When the latter was raised to 100° Centigrade (212° Fahr.) the fire, together with the plate, was removed, and a quantity of finelydivided stearic acid was strewed over the impression by means of a sieve. The powder used was that of a common stearine candle, dissolved by heat in alcohol, and then thrown into a large quantity of cold water, when the stearine falls to the bottom in the form of a fine precipitate. This powder is so light and impalpable, that it is said it might be sifted over an impression in the dust of a common road, without, in the slightest degree, interfering with the faintest mark. The instant it touched the heated surface of the ground in question it melted, and, as it were, sealed the whole of the loose atoms into one compact mass. When a sufficient quantity of the stearine had been applied, the place was left until it had become completely cold; the surrounding earth was then dug out carefully at some little distance from the and saves the face. The next instant throw the edges of the impression, and the portion contain- unfortunate person on the floor. This is an ading this latter was lifted up in one entire block,ditional safety to the face and breath, and any remand laid on a cloth several times doubled, the nant of flame can be put out more leisurely. The edges of which were raised up so as to form a kind next instant, immerse the burnt part in cold water, of border, or rather framing, into which, and and all pain will cease with the rapidity of lightagainst the sides of the sandy earth containing the ning. Next, get some common flour, remove from impression, plaster of Paris was poured; and the water, and cover the burnt parts with an inch when the latter was set, the whole could be han-thickness of flour, if possible; put the patient to dled without danger, and was firm enough to bear packing and carriage to any distance. It is evident, therefore, that if necessary it might also be used as a mould, from which casts in plaster could be obtained. The value of such a process, as an aid in criminal cases, is too self-evident to require demonstration; the production of the tell-tale impressions in a court of justice, where every mark can be conveniently exhibited and compared with the object by which it was produced, may be equally useful in the proof of guilt and of innocence, and it would be strange, indeed, if a use for such a process be not discovered in matters of scientific or practical interest. To make Writing Indelible. The following simple process will make leadpencil writing or drawing as indelible as if done with ink. Lay the writing in a shallow dish, and pour skimmed milk upon it. Any spots not wet at first may have the milk placed upon them lightly with a feather. When the paper is all wet over with the milk take it up and let the milk drain off, and whip off with the feather the drops which collect on the lower edge. Dry it carefully, and it will be found to be perfectly indelible. It cannot be removed even with India-rubber. It is an old recipe and a good one. To render Paper Fire-proof. Whether the paper be plain, written, printed on, or even marbled, stained, or painted for hangings, dip it in a strong solution of alum-water, and then thoroughly dry it. In this state it will be fireproof. This will be readily known by holding a slip thus prepared over a candle. Some paper requires to imbibe more of the solution than by a single immersion, in which case the dipping and drying must be repeated until it becomes fully saturated. Neither the color nor quality of the bed, and do all that is possible to soothe until the physician arrives. Let the flour remain until it falls off itself, when a beautiful new skin will be found. Unless the burns are deep, no other application is needed. The dry flour for burns is the most admirable remedy ever proposed, and the information ought to he imparted to all. The principle of its action is that, like the water, it causes instant and perfect relief from pain, by totally excluding the air from the injured parts. Spanish whiting and cold water, of a mushy consistency, are preferred by some. Dredge on the flour until no more will stick, and cover with cotton batting. To Bleach Sponges. Wash in hot dilute soda lye; then immerse in dilute muriatic acid, 1 part to 10 of water, until all gritty particles are removed, and no more gas arises; then immerse in a second bath of dilute muriatic acid, containing 3 per cent. of hyposulphite of soda, for 48 hours. To take out Mildew. Wet the linen where spotted in Labarraque's Solution (solution of chlorinated soda), or solution of chloride of lime (bleaching salt), or chlorine water; it will immediately disappear. Wash out at once with warm water. This is a better plan than that given in p. 314. Fruit and wine sains of all kinds may be removed in the same manner. Simple Mode of Purifying Water. A tablespoonful of pulverized alum sprinkled into a hogshead of water (the water stirred at the same time) will, after a few hours, by precipitating to the bottom the impure particles, so purify it that it will be found to possess nearly all the freshness and clearness of the finest spring-water. A pailful, containing 4 gallons, may be purified by a single teaspoonful of the alum. Another. Add to a hogshead of water a tablespoonful of a saturated solution of permanganate of potassa; this effectually destroys all organic matter. If the water retain a pink hue, put a stick or chip in it when the color will shortly disappear. To Cure Dry-rot in Timber. Saturate the wood in a weak solution of copperas, for joists, beams, rafters, and floorings; or, soak the wood in lime-water, suffering it to dry, and then apply water in which there is a weak solution of vitriolic acid; or wash it with a strong solution of potash, then with pyroligneous acid in which the oxide of lead or iron has been dissolved; and finally, with alum-water. A current of air under a floor will always prevent the dry-rot, and stop it when it has commenced. In boarding kitchens and other rooms on the basement story, the planks should be steeped in a strong solution of vitriol or alum, and when they are dried, the side next to the earth should receive a coat of tar or common paint. Solutions used in Preserving Timber. The following have been employed. They are forced into the pores of the wood by putting it into a close vessel, exhausting the air, and then allowing the liquid to flow in. In some cases the timber is merely immersed; in others the liquid flows in under heavy pressure. In Bouchérie's method the green tree is felled, the branches trimmed off, and a bag containing sulphate of copper or other antiseptic agent attached to the butt. The sap is gradually expelled by displacement, and flows from the free end of the log, the antiseptic solution taking its place. These solutions probably act by coagulating the albuminous matters of the wood, and thus preventing the beginning of decay or dry-rot. They also prevent the attacks of insects. Corrosive sublimate (Kyan), chloride of zinc (Burnett), sulphate of copper (Bouchérie), chloride of calcium, followed by sulphate of iron (Payne), crude pyroligneous acid, saturated with iron scraps (Bethell), coal tar. Prevention of Decay in Timber. Well-seasoned timber may be preserved by charring the surface. The process adopted in the French dockyards is to use a jet of mixed coal-gas and air; the two being conveyed by India-rubber tubes, which unite at the jet. The air is forced in by a bellows worked by the foot of the operaA slight previous coating of tar is useful by filling up cracks, and causing a uniformity of action of the flame. tor. To Check the Warping of Planks. The face of the planks should be cut in the di rection from east to west as the tree stood. The strongest side of a piece of timber is that which, in its natural position, faced the north. To Get Oil out of Boards. Mode of Detecting Decay in Timber. The Cosmos reports from the other journals a simple mode, said to have been adopted from immemorial times in the ship-yards of Venice, for ascertaining the fitness of timber for their constractions. "A person applies his ear to the middle of one of the ends of the timber, while another strikes upon the opposite end. If the wood is sound and of good quality, the blow is very distinctly heard, however long the beam may be. If the wood were disaggregated by decay or otherwise, the sound would be for the most part destroyed. To Preserve Polished Irons from Rust. by a mixture not very expensive, consisting of Polished iron-work may be preserved from rust copal varnish intimately mixed with as much olive-oil as will give it a degree of greasiness, adding thereto nearly as much spirit of turpen tine as of varnish; or varnish with wax dissolved in benzine. The cast-iron work is best preserved by rubbing it with black-lead. But where rust has begun to make its appearance on grates or fire-irons, apply a mixture of tripoli, with half its quantity of sulphur, intimately mingled on a marble slab and laid on with a piece of soft leather; or emery and oil may be applied with excellent effect; not laid on in the usual slovenly way, but with a spongy piece of the fig-tree fully saturated with the mixture. This will not only clean, but polish, and render the use of whiting unnecessary. To Preserve Brass Ornaments. The Brass ornaments, when not gilt or lackered, may be cleaned in the same way, and a fine color may be given to them by two simple processes. first is to beat sal ammoniac into a fine powder, then to moisten it with soft water, rubbing it on the ornaments; which must be heated over charcoal and rubbed dry with bran and whiting. The second is to wash the brass work with roche alum boiled in strong lye, in the proportion of an ounce to a pint. When dry it must be rubbed with fine tripoli. Either of these processes will give to brass the brilliancy of gold. Easy Mode of Taking Impressions from Coins, eto A very easy and elegant way of taking the impressions of medals and coins, not generally known, is thus described by Dr. Shaw: Melt a little isinglass glue with brandy, and pour it thinly over the metal so as to cover its whole surface; let it remain on for a day or two, till it is thoroughly dried and hardened, and then taking it off it will be fine, clear, and as hard as a piece of Muscovy glass, and will have a very elegant impression of the coin. It will also resist the effects of damp air, which occasions all other kinds of glue to soften and bend if not prepared in this way. Adamas, A substitute for metal in the manufacture of gasburners, journal bearings, taps, etc., is made of and annealed. Mix together fuller's earth and soap lees, and finely-powdered soapstone, pressed into moulds rub it into the boards. Let it dry and then scour it off with some strong soft soap and sand, or use lees to scour it with. It should be put on hot, which may easily be done by heating the lees. To Prevent the Splitting of Logs and Planks. Logs and planks split at the ends because the exposed surface dries faster than the inside. Saturate muriatic acid with lime and apply like whitewash to the ends. The chloride of calcium formed attracts moisture from the air, and prevents the splitting. Soapstone Powder as a Lubricator. Soapstone powder, in the form of dust, is proposed as a lubricant for the axles of machines. For this purpose it is prepared as follows: It is first reduced to the condition of very fine powder; then it is washed to remove all gritty particles; then it is steeped for a short period in dilute muriatic acid (about 1 qt. of acid to 20 of water), in which it is stirred until all particles of iron which it contains are dissolved. The powder is then washed in pure water again, to remove all traces A New Kind of Electric Machine. The electro-magnetic coil has, in a great measure, superseded the electric machine; the latter, however, will never cease to be an object of of acid; then it is dried, and is the purified steatite powder used for lubrication. It is not used alone, but is mixed with oils and fats, in the proportion of about 35 per cent. of the powder, added to paraffine, rape, or other oil. This steatite pow-interest; and, it is probable, will always be preder, mixed with any of the soapy compounds, which are also now used, in many cases, for lubrication, also answers a good purpose. It is chiefly intended for heavy machinery, such as the journals of water-wheels, railway and other carriages. Ransome's Artificial Stone. Make sand or gravel into a paste with fluid silicate of soda (water-glass), mould it to the desired shape, and dip into a solution of chloride of calcium. This solution is made by neutralizing muriatic acid with lime, chalk, limestone, or marble. The mass becomes solid in a few minutes, and is exceedingly strong and durable. To Imitate Ground Glass. A ready way of imitating ground glass is to dissolve Epsom salts in beer, and apply with a brush. As it dries it crystallizes. To Drill Glass. Wet an ordinary drill with petroleum or benzine; turpentine will answer, but not so well; it will then bore common glass nearly as rapidly as steel. If it is intended to bore through, the glass should be first countersunk on each side with a drill dressed off so as to form a very flat threesided pyramid. Flint and plate-glass are very difficult to bore. ferred for some purposes. The expense and difficulty of managing large plates and cylinders of glass have hitherto been obstacles to the use of large electric machines. These obstacles appear now removed-glass being rendered unnecessary by the discovery of a far more convenient and effective material. M. Edmond Bequerel exhibited to the Academy of Sciences on a recent occasion an electric machine, the plate of which was made of indurated red sulphur, the invention of a civil engineer. It was 80 centimetres in diameter, and afforded a spark 14 centimetres in length. No amalgamated cushions were required with it, the skin of a cat being quite sufficient to produce every desired effect. Sulphur undergoes extraordinary changes by successive fusions; becoming extremely hard and tenacious. After the third fusion it no longer acts on metals, or possesses its characteristic odor. The plate used by M. Bequerel was formed by fusing the sulphur 3 times in a cast-iron vessel, at a temperature between 250° and 300° Cent., and allowing it, after each fusion, to cool thoroughly. After the 1st and 2nd fusions it was crushed to a coarse powder; and, after the 3rd, it was poured into a plaster-mould. Plates, 4 metres in diameter, may easily be made in this way; they cost extremely little; and, besides being more efficient, are far less hygrometric than glass. WEATHER PROGNOSTICS. TO CONSTRUCT BAROMETERS. The tubes intended for barometers ought to be sealed hermetically on both ends, immediately after they are made at the glass-house, and to be kept in this state until they are fitted up. With out this precaution they are apt to be sullied with dust, moisture, and other impurities, which it is afterwards almost impossible to remove on account of the smallness of their diameters. When they are opened, which may be done with a file, care should be taken not to breathe into them, nor to wash them with spirit of wine, or other fluid, experience having proved that in tubes so treated, the mercury always stands a little below its proper level; this is owing to the adhesion of a little of the spirit of wine to the sides of the tube. When cleaning is necessary, it must be done with a fine linen rag that has been previously well dried. The tubes ought to be as perfectly cylindrical as possible, though, in some cases, this is not absolutely necessary. They should be about 33 inches in length, and the diameter of their bore should be at least 2 or 24 lines, otherwise the friction, and the capillary action will be apt to affect the free motion of the mercury. The glass should not be very thick, as it is apt in that case to break; when the mercury is boiled in the tube half a line is sufficient. The mercury ought to be perfectly pure and free from all foreign metals. The best is that which has been recently revived from cinnabar; the common mercury of the shops being often adulterated intentionally with tin, lead, and bismuth, stands at various heights in the tube, according to the nature and quantity of the foreign substances with which it is amalgamated. To Obtain the Mercury Pure. For this purpose take a pound of cinnabar and reduce it to powder; mix it well with 5 or 6 oz. of iron or steel filings; and, having put the mixture into an iron retort, expose the whole to the heat of a reverberatory furnace; the mercury will soon pass over in a state of great purity, and may be obtained by adapting to the retort an earthen receiver, which has been previously half filled with water. Commercial mercury may be purified by distilling it over a portion of cinnabar. These are put into an iron bottle with an iron tube attached; to the end of the iron tube is one made of leather or India-rubber which dips beneath the surface of water constantly renewed. Process of Filling the Tube. Before being introduced into the tube, the mercury ought to be well heated, or even boiled in a glazed earthen pipkin, in order to drive off any moisture which may adhere to it, but this will be unnecessary if the mercury has been recently reduced. The mercury ought likewise to be boiled in the tube to expel any air or moisture which may still remain attached to it, or to the inside of the tube. This is done in the following manner: Pour as If a long pipe, closed at one end only, were emptied of air, filled with water, the open end kept in water, and the pipe held upright, the water would rise in it more than 30 feet. In this way water barometers have been made. A proof of this effect is shown by any well with a suckingpump, up which, as is commonly known, the water will rise nearly 30 feet by what is called suction, which is, in fact, the pressure of air towards an empty place. much mercury into the tube as will make it stand to the length of 3 or 4 inches; and introduce a long wire of iron to stir it during the boiling. Expose the mercury in the tube gradually to the heat of a chafing-dish of burning charcoal, or a well regulated gas flame; and when it begins to boil, stir it gently with the iron wire, to facilitate the disengagement of the bubbles of the air. When the first portion of the mercury has been sufficiently boiled, and all the air extricated, remove the tube from the chafing-dish and allow the whole to cool, taking care not to bring it into contact with any cold substance. Introduce an equal quantity of mercury, and treat it in the same manner, withdrawing the wire a little so that it may not reach below the upper part of the mercury already freed from air. The chafing-dish must also be placed immediately under the mer-"fair," and then fall, it presages a change, though cury which has been last poured in. Repeat the same process with each successive portion of mercury till the tube is filled, always applying the heat very cautiously; and be equally careful in allowing it to cool before a fresh portion of mercury is poured in. The Aneroid Barometer The words on scales of barometers should not be so much regarded for weather indications as the rising or falling of the mercury, for if it stand at "changeable," and then rise towards "fair," it presages a change of wind or weather, though not so great as if the mercury had risen higher; and, on the contrary, if the mercury stand above not to so great a degree as if it had stood lower; besides which, the direction and force of the wind are not in any way noticed. It is not from the point at which the mercury may stand that we are alone to form a judgment of the state of the state of the weather, but from its rising or falling, and from the movements of immediately preced Consists of a brass-box partially exhausted of airing days, as well as hours, keeping in mind effects with an elastic lid of corrugated brass. Changes of atmospheric pressure are indicated by the movements of the lid which are transmitted to an index hand. It is light, portable, contains no liquid, and is more sensitive than the mercurial barometer. READING THE BAROMETER. The following manual of the barometer has been compiled by Rear-Admiral Fitzroy, and published by the Board of Trade. It has been slightly altered to suit the climate of the United States. 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 usually fortells less wind or rain, a falling barometer more rain or wind, or both; a high one fine weather, and a low one the contrary. But useful as these general conclusions are in most cases, they are sometimes erroneous, and then remarks may be rather hastily made, tending to discourage the inexperienced. By attention to the following observation (the results of many years' practice, and many persons' experience), any one not accustomed to use a barometer may do so without difficulty. The barometer shows whether the air is getting lighter or heavier, or is remaining in the same state. The quicksilver falls as the air becomes lighter, rises as it becomes heavier, and remains at rest in the glass tube while the air is unchanged in weight. Air presses upon everything within about 40 miles of the world's surface, like a much lighter ocean, at the bottom of which we live, not feeling its weight because our bodies are full of air, but feeling its currents, the winds. Towards any place from which the air has been drawn by suction, air presses with a force or weight of nearly 15 lbs. on a square inch of surface. Such a pressure holds the limpit to the rock when, by contracting itself, the fish has made a place without air 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 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 30 inches (more or less) in the tube, where no air presses on the top of the column. of change of direction and dryness or moisture, as well as alteration of force or strength of wind. latitudes, the quicksilver ranges, or rises and falls, In this part of the world, towards the higher nearly three inches-namely, between about thirty inches and nine-tenths (30.9), and less than twenty-eight inches (28.0) on extraordinary occasions; but the usual range is from about thirty inches and a half (30.5) to about twenty-nine inches. Near the Line, or in equatorial places, the range is but a few tenths, except in storms, when it sometimes falls to twenty-seven inches. The sliding scale (Vernier) divides the tenths into 10 parts each, or hundredths of an inch. The number of divisions on the Vernier exceeds that in an equal space of the fixed scale by one. By a thermometer the weight of air is not shown. No air is within the tube, none can get in. But the bulb of the tube, is 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. If a thermometer have a piece of linen 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. In very damp weather, with or before rain, fog, or dew, a wet and dry bulb thermometer will be nearly alike. For ascertaining the dryness or moisture of air, the readiest and surest method is the comparison of two thermometers, one dry, the other just moistened and kept so. Cooled by evaporation as much as the state of the air admits, the moist (or wet) bulb thermometer shows a temperature nearly equal to that of the other one, when the atmosphere is extremely damp or moist; but lower at other times in proportion to the dryness of air and consequent evaporation-as far as 12° or 15° in this climate, 20° or even more elsewhere. From 4° to 8° of difference is usual in England, and about 7° is considered healthy for inhabited roɔms. The wet and dry bulb thermometer on the same frame, the water being supplied by a bird fountain, constitutes August's or Mason's hygrometer. The thermometer fixed to a barometer intended to be used only as a weather-glass, shows the temperature of air about it, nearly, but does not show the temperature of mercury within, exactly. It does so, however, near enough for ordinary practical purposes, provided that no sun, nor fire, nor lamp heat is allowed to act on the instrument partially. The mercury in the cistern and tube being af fected by cold or heat, makes it advisable to consider this when endeavoring to foretell coming weather by the length of the column. Briefly, the barometer shows weight or pressure of the air; the thermometer, heat and cold, or temperature; and the wet thermometer, compared with a dry one, the degree of moisture or dampness. It should always be remembered that the state of the air foretells coming weather rather than shows the weather that is present-an invaluable fact too often overlooked; that the longer the time between the signs and the change foretold by them, the longer such altered weather will last, and, on the contrary, the less the time between a warning and a change, the shorter will be the continuance of such foretold weather. To know the state of the air not only barometers and thermometers should be watched, but the appearance of the sky should be vigilantly noticed. If the barometer has been about its ordinary height, say near 30 inches (at the sea level), and is steady, or rising while the thermometer falls, and dampness becomes less, northwesterly or northerly wind, or less wind, less rain or snow may be expected. On the contrary, if a fall takes place with a rising thermometer and increased dampness, wind and rain may be expected from the south-eastward, southward or south-westward. A fall with a low thermometer foretells snow. A rise during frost indicates snow. A rapid rise of the barometer indicates unset. tled weather, a slow movement the contrary; as likewise a steady barometer, which, when continued, and with dryness, foretells very fine weather. The greatest depressions of the barometer are with gales from S. E., S., or S.W.; the greatest elevations, with wind from N.W., N., or N.E., or with calm. Though the barometer generally falls with a southerly and rises with a northerly wind, the contrary sometimes occurs; in which cases, the southerly wind is usually dry with fine weather, or the northerly wind is violent and accompanied by rain, snow or hail; perhaps with lightning. When the barometer sinks considerably, much wind, rain (perhaps with hail) or snow will follow; with or without lightning. The wind will be from the northward, if the thermometer is low, (for the season), from the southward if the thermometer is high. Occasionally a low glass is followed or attended by lightning only, while a storm is beyond the horizon. A sudden fall of the barometer with a westerly wind, is sometimes followed by a violent storm from N.W., or N., or N.E. If a gale sets in from the E. or S.E., and the wind veers by the S., the barometer will continue falling until the wind is near a marked change, when a lull may occur, after which the gale will soon be renewed, perhaps suddenly and violently, and the veering of the wind towards the N.W., N., or N.E., will be indicated by a rising of the barometer with a fall of the thermometer. Three causes (at least) appear to affect a barometer: 1. The direction of the wind; the northeast Exceptions to these rules occur when a north-wind tending to raise it the most, the southwest to easterly wind with wet (rain, hail or snow) is impending, before which the barometer often rises (on account of the direction of the coming wind alone) and deceives persons, who from that sign only (the rising) expect fair weather. When the barometer is rather below its ordinary height, say down to near 29 inches (at the sea level), a rise foretells less wind, or a change in its direction toward the northward, or less wet; but when it has been very low, about 29 inches, the first rising usually precedes or indicates strong wind; at times heavy squalls from the northwestward, northward or northeastward, after which violence a gradually rising glass foretells improving weather, if the thermometer falls; but if the warmth continue, probably the wind will back (shift against the sun's course) and more southerly or southwesterly wind will follow, especially if the barometer's rise is sudden. lower it the most, and wind from points of the compass between them proportionally as they are nearer one or the other extreme point. N.E. and S.W. may, therefore, be called the wind's extreme bearings. The range or difference of height shown, due to change of direction only, from one of these bearings to the other (supposing strength or force and moisture to remain the same), amounts in these latitudes to about an inch (as read off). 2. The amount taken by itself of vapor (moisture, wet, rain, or snow in the wind remaining the same), seems to cause a change amounting in an extreme case to about an inch. 3. The strength or force alone of wind, from any quarter (moisture and direction being unchanged), is preceded or foretold by a fall or rise, according as the strength will be greater or less, ranging in extreme cases to more than 2 inches. The most dangerous shifts of wind or the heavi- Hence, supposing three causes to act together, est northerly gales happen soon after the barome-in extreme cases, the height would vary from er first rises from a very low point, or if the wind veers gradually at some time afterwards. Indications of approaching changes of weather and the direction and force of winds are shown less by the height of the barometer than by its falling or rising. Nevertheless, a height of more than thirty (30.0) inches (at the level of the sea) is indicative of fine weather and moderate winds, except from east to north occasionally or during frost, when northeast winds and snow are indicated. 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; or when the hand of the wheel barometer or Aneroid moves to the left. The barometer is rising when the mercurial column is lengthening, its upper surface being convex or rounded, or when the hand moves to the right. near 31 in. (30-9) to about 27 in. (27-0), which has happened, though rarely (and even in tropical latitudes). In general the three causes act much less strongly, and are less in accord, so that ordinary varieties of weather occur much more frequently than extreme changes. Another general rule requires attention, which is, that the wind usually appears to veer, shift, or go round with the sun (right-handed, or from left to right), and that when it does not do so, or backs, more wind or bad weather may be expected, instead of improvement. It is not by any means intended to discourage attention to what is usually called "weather wisdom." On the contrary, every prudent person will combine observation of the elements with such indications as he may obtain from instruments, and will find that the more accurately the |