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common language it is described as having boiled exposed to its influence. With the aid of an airaway.

pump (an instrument whose principle and uses we That warm water is specifically lighter than cold, intend to explain at no very distant period) it can may be shown, if we take an ale-glass and pour into be shown that water may be kept in a state of it a small quantity of cold water. Placing in the ebullition when its temperature is equal only to 72°. glass a thin piece of cork, pour gently upon it, Alcohol, in like manner, may be made to boil at through a funnel, some warm water which has been 33°, and ether at 44° below zero,—that is seventytinged by a few drops of the infusion of red cabbage, five degrees lower than (32) the freezing-point of litmus, or saffron. Above this, pour in the same water. manner, a little more water, much hotter than the We have already hinted that boiling and scalding last, but which has not been coloured. If the glass are not synonymous terms. This may be demonremain undisturbed, the three several portions of strated in the following manner. Pour some boiling water will preserve for some time their relative water into a glass vessel, and mix with it cold water situations, namely, the cold water will remain at the until its temperature is reduced to 180°; leaving a bottom, that which has been coloured, in the middle, thermometer in the vessel, place it under the receiver and that still hotter, at the top: If we now take of an air-pump. When some of the air has been some cold water, which has been tinged of a different withdrawn, the water will commence boiling. If colour from that just mentioned, and pour it very the exhaustion of the air be continued, the water slowly against the side of the glass, it will pass by will boil until the thermometer sinks to about 720,the warm water, already in the glass, and mix itself a temperature that is well known to be very much with the cold at the bottom.

lower than scalding. By the preceding table, it will be seen that the A still more striking illustration of the effect of temperature at which water boils is 212°. We have atmospheric pressure upon liquids may be thus peralready mentioned that a variety of circumstances formed :-put a little cold water into a thin glassconcur to affect the boiling point of all liquids ; but vessel (a watch-glass will answer the purpose very as the phenomena connected with water are better well) and into a similarly-shaped vessel, if metallic, known than any other, we shall allude to that liquid so much the better, pour about an equal quantity more particularly.

of ether. The vessel containing the ether must be The material of which the containing vessel is stood within the other, and both be placed under the constructed will influence the boiling-point of water. receiver of an air-pump. On withdrawing the air, In a metallic vessel it will boil at 212°. In a glass the ether will boil briskly,—soon disappearing in the vessel, to produce the same result, its temperature form of vapour. If the experiment is properly must be raised to 214°. The addition of a few conducted, on re-admitting the air, and removing particles of some solid substance will alter the boiling the receiver, the water in the glass vessel will be point. Thus, when water is boiling in a glass vessel found to be frozen. at 214°, if we cast into it a few iron-filings, ebullition In our next paper we must resume this subject; will continue as before, but the temperature of the the space here allotted us being insufficient for enterwater will instantly fall to 212o.

ing so fully into it as we desire, and as will, we When the barometer* stands at 30 inches, at the hope, be acceptable to our readers. Before we conmean level of the earth, all bodies on the earth's clude, we purpose, however, describing another very surface, being at the same elevation, are exposed to interesting experiment, in proof, not only that water pressure from the atmosphere equal to 15 lbs. on will boil at a very low temperature, but, what may every square inch. This pressure has a powerful appear still more extraordinary, that when it has effect in controlling the vaporization of liquid bodies. ceased boiling, it may be made to recommence, by As the pressure of the atmosphere is liable to fre- plunging the vessel containing it into cold water. quent variations, we find the boiling points of liquids Having provided two glass vessels, c and D, let c are similarly affected.

It is only when the mercury in the barometer-tube stands at 30 inches, that water boils at 212°. When the mercury rises in the tube, it is because the pressure of the air is increased, and then the boilingpoint is greater than 212°. When the mercury

D descends, the pressure of the air is diminished, and then the boiling-point is less than 212°. In Great Britain the barometer is scarcely ever lower than 281 inches, or higher than 31 inches. As the boilingpoint of water is affected about fth (one-sixth) of a degree of Fahrenheit's Thermometer, for every iģth (one-tenth) of an inch variation of the barometer, its changes are limited in this country to about 4+ or be about three-fourths filled with boiling water, 5 degrees. When the barometer is at 284 inches, and d with an equal quantity of cold water.-Take water will boil at 209}; when it is at 31 inches, the a flask, as denoted by the figure. E, to the neck of temperature of boiling water will be 2134o. As we

which must be accurately fitted a cork, covered with ascend in the atmosphere, the pressure above us wax, or a piece of moistened bladder : if a stop-cock diminishes. Those who live in mountainous regions, be adapted to the flask, it will be still better. Pour employ less beat to make liquids boil than those who into the flask a sufficient quantity of water to occupy inhabit the valleys beneath them. At Madrid the about one-fourth of its space. Leaving the stopboiling-point of water is about 208°, at Mexico it is cock open, or the cork out, as the case may be, 198°, and on the summit of Mont Blanc 187o.

apply heat, say with a spirit-lamp, to the bottom of When the weight of the atmosphere is altogether the flask, until the water boils. Removing the lamp, removed froin the surfaces of liquids, they boil at a close quickly the mouth of the flask, and when the temperature about 140° lower than when they are ebullition of the water has ceased, plunge the flask, as • See Saturday Magazine, Vol. IV., pp. 11, 63.

low as possible, into the cold water, in the vessel D.

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The water will instantly recommence boiling as

MANUFACTURE OF SAGO. briskly as ever. Remove the flask to the hot water SINGAPORE is the principal, if not the only place in in c, the boiling will cease ; return it again to , it the East where the manufacturing of the Pearl Sago will be resumed ; and this alternation may be con

is carried on, and the process is said to be a recent tinued until the temperature of the water in the

one, and the invention of the Chinese. flask is reduced to about 72o. Covering the hands The Sago is imported in large quantities into Singawith worsted gloves will enable the operator to pore from Sumatra in native boats, which bring it at handle the flask without any inconvenience from its all times of the year. The tree from which the raw heat.

material is produced is named Rumbiga by the The curious effect thus produced by putting the flask into cold water is dependent on the elasticity The raw Sago is imported in cone-shaped packages, of the vapour of boiling water, in conjunction with each probably weighing about twenty pounds; the its speedy condensation. When the water is first

mass is of rather a soft consistence, and dirty-white made to boil, the vapour arising from it is sufficiently colour, and the whole enveloped in the leaves of the elastic to force out the air from the flask, and to Pandanus-tree. It first undergoes several different occcupy its place. On surrounding the flask with washings in large wooden tubs, being also strained, cold water, the vapour in it is suddenly condensed after washing, through cloth strainers; the masses (that is, it returns to its liquid state) leaving above that remain at the bottom of the vessels are collected, the surface of the water, a vacant space (vacuum) | broken into pieces, and placed upon platforms in the similar to that produced by an air-pump. By placing sun to dry, being broken into still smaller pieces as the flask in hot water, vapour is again formed, which the drying proceeds. As soon as the pieces are sudpressing on the surface of the liquid, prevents ebul- ficiently dry, they are pounded, and sifted upon long sition. Again it may be condensed—a vacuum is benches, through sieves made of the mid-rib of the produced—and the water will boil as before.

leaves of the cocoa-nut palm, and placed at certain R. R. distances in a longitudinal direction, so as to cause

the pulverized, or rather broken, masses of Sago, to ON THE MISUSE OF TERMS.

pass through it only of the required size. Having On men of ingenuous but inexperienced minds, each time is taken, placed in a large cloth, tied to

been passed through the sieve, a certain quantity at there is nothing so imposing as a specious name. In private life, some are brought into great distress, from the roof of the building; a Chinese is then

cross-sticks in the form of a bag, hanging by a cord from having acted under an idea that inattention to employed in shaking the bag backwards and forpecuniary concerns was a mark of generosity. Others wards, by the aid of one of the longest crooked fall into vicious practices, because easy compliance sticks to which it is attached, occasionally shaking with every proposal of a companion appears to them a proof of good temper. Others commit irregu- for the space of ten minutes, when it is turned out

up the Sago Powder ; this is continued constantly larities, through a persuasion that to despise the granulated; it is then placed in small wooden hand. uniformity of rules is an indication of high spirit. tubs, (looking beautifully and delicately white, but Others violate the decencies of politeness, conceiving still so soft as to break instantly on the slightest disregard to forms a sign of superior ability. Then, again, in public life; many do in reality serve the pressure,) and carried to several Chinese, whose occucause of licentiousness, whilst with the purest in- pation is to make it undergo the drying process in tentions they mean only to extend liberty: and many stirring it about while in the pan with a wooden in,

large iron pans over a fire. They are constantly give encouragement to indifference for all religion, strument; it is then resifted at another bench, and whilst they imagine themselves to be promoting only rebaked, after which it is considered prepared. It is liberality of sentiment.

then of a fine pure white colour, and, being spread Now, in the one case, admirable are generosity, good thinly over a long and large bin, in the course of temper, high spirit, and superior ability; but surely, time becomes both harder and of a darker colour. no man in his right senses can say it is admirable,

The Pearl, or refined Sago, is exported in large either to bring on himself indigence through im- quantities to Europe, our Indian empire, the Cape,

of depraved through weakness, in yielding to solicita &c., in wooden boxes, each containing rather more tions; or to injure society by bad example; or to manufactured in two days.

than a pecul ; ten boxes, or fifteen peculs, can be insult established usages of behaviour by an affected So, in the other case, liberty is the inhabitants of which must fare very well on the

A piggery is attached to the Sago establishments, impertinence. precious in itself; and liberality in thinking and judging is part of Christian charity, than which refuse of the Sago-washings. nothing is more lovely: but, surely, no man of mature judgment can wish genuine liberty to be converted into a cloak for every species of enormity;

SIMPLE WATER-FILTER. nor liberality of sentiment be made the occasion of Put into an earthen vessel, such as those which are used propagáting direct atheism. Yet in these points of by sugar-bakers to form the loaves in, with a small hole at view are to be seen many measures which upright the pointed end, some pieces of Turkey sponge, and on them but misguided men frequently pursue, merely be a sufficient quantity of small, CLEAN pebbles, to a quarter cause they do not fully apprehend the tendencies of fill the vessel. Suspend this filter, the end downwards,

in a barrel with the hcad out, leaving about two or three their actions.-BISHOP HUNTINGFORD.

inches space between the end of the filter and the bottom of the barrel. The upper part of the filter must be kept a

little above the top of the barrel, which should be always EXEMPTION from mistake is not the privilege of mortals. full of water. It is obvious that the sediment of the water but when our mistakes are involuntary, we owe each other will remain at the bottom of the barrel, and the pure water every candid consideration; and the man who, on discover will ASCEND through the sponge and pebbles, to the uning his errors, acknowledges and corrects them, is scarcely occupied portion of the filter. It might be suspended in a less entitled to our esteem than if he had not erred.- cistern or water-butt, if more convenient. The pebbles and PYE Smith,

sponge should be cleansed occasionally.

COAL AND COAL MINES.

THE BEAR AND THE HONEY-GUIDE *.

A FABLE. The vein or bed of coal is generally seven or eight feet thick; and through this the workmen form a variety of

THERE is a bird of wondrous skill, passages, leaving masses at intervals untouched, to support

Half-reas’ning instinct, if you will, the roof, so that the whole resembles a vast subterranean

Whose hoine is in a distant spot, palace, supported by ebony pillars. Some of them are wide

The country we call Hottentot: enough to admit carts and wagons; and as you walk above,

Her taste is nice ; for she can tell you hear the busy world below you, the buzz of voices, and

Where the sweet honey-makers dwell, the rumbling of wheels ascending as from some neigh

And, greedy pilferer! feasts and thrives bouring city. The streets or ramifications of this mine, are

Upon the produce of the hives ; said to extend in various directions for nearly twenty miles,

In what a bold and cunning way, both under the sea and under the town of Whitehaven, so

Shall form the opening of my lay. as to become dangerous to the latter.

Strange it may seem, and yet 'tis true, But how can they see to work in the darkness ?

That Bears are ford of honey too, This is a circumstance which has greatly embarrassed

But stranger that a Bird should lead the miners. The nature of coal is such, that it produces

The way, and show them where to feed. different airs or gases that are highly dangerous to human

She, watchful thing, the treasure found, life; one is called the choke-damp, and the other the fire

Hov'ring above, below, around, damp. Where a man incautiously breathes the first, he is

Invites the Bear with plaintive cries, speedily suffocated. When he brings any light to the second,

To follow her and seize the prize. it immediately explodes like gunpowder; sometimes it

Lured by the magic of her song, dashes the body against the roof or pillars with great

The shaggy monster strides along, violence; sometimes it tears it, as it were, to pieces.

Paws out the honey, licks the nest, The approach of these ministers of death is frequently

And leaves his guide to eat the rest. as insidious as it is destructive. At one time an odour

E'en such an ill-match'd pair I choose of the most fragrant kind is diffused through the mine,

To point the moral of my Muse. resembling the scent of the sweetest flowers; and while the

“Come!” said a HONEY-GUIDE, “and see miner is inhaling the balmy gale, he is suddenly struck

The banquet I design for thee : down, and expires in the midst of his fancied enjoyment.

The nest is large, its sweets untold, At another it comes in the form of a globe of air, enclosed

Flowing in streams of liquid gold : in a filmy case; and while he is gazing on the light and

The bees are gone where wild flowers shine, beautiful object floating along, and is tempted to take it in

And wish their luscious product thine: his hand, it suddenly explodes, and destroys him.

Then, gentle Bruin, do not stay, I have heard there is some coal which itself emits, when

Come, dear companion, come away!” burning, a gas that is very unsafe.

When she deceived and fooled him so, · There is a kind of coal in Ireland, little known in

What wonder that the Bear should go ? England, which has this property. It is found in the county

They went; he keeping her in sight, of Kilkenny, and called stone-coal, because it resembles

She with a cautious, clamorous flight, blocks of jasper or jet, being very hard, shining, and clean.

Till in broad sunshine they arrive It has the peculiar advantage, also, of yielding no dense or

Like felons at the quiet hive. sulphurous vapour; so that the people of the towns where

Young Bruin, in his headlong haste, it is raised and consumed, justly boast that they have “fire

Impatient to attack and taste, without smoke.” This good quality, however, is counter

Fells the slight fabric at a blow ;acted by one of a different kind: in the act of burning, it

But while he sipp'd the sweets that flow,emits an invisible gas, which it is highly dangerous to

From cells within, an armed throng breathe, and which in a close room destroys life, as you have

Pour'd in a countless crowd along, heard the vapour of charcoal does. On entering the town

And fixing on the culprit, stung of Kilkenny, in certain states of the atmosphere, on a

His broad, dark nose, his eyes, his tongue. winter's day, when a great quantity of this coal is burning

Sharp anguish mounting to his brain, at the same time, and the atmosphere entirely filled with

He roar'd, and even danced for pain, its vapour, a nervous and very uneasy sensation is felt, and

Then prowl'd in blindness o'er the plain ! a debility nearly amounting to fainting. I remember, on

And thou, unkind one on the spray, one occasion, travelling through on a stage-coach on a very

False bird, bast nothing now to say ? severe day; we all hastened to a large fire, which was

Bringing another into woe,

What ? not one word of comfort ? No! burning very bright and red in the parlour, and immediately complained that we felt this sensation very strongly; but a

Eyeing her victim with a sneer,

And waiting till the course was clear, laily of the company, who said she was very cold, incautiously remained with her head and hands over the fire ;

She pounced upon the relics there, when she was seized with a sudden faintness, and fell as if

And filled her crop with ill-got fare.

Poor BRUIN lives ;-but should he hear she were dead: on being brought out to the air she recovered.

A HONEY-GUIDE's shrill music near, The people of the inn told us it was not an uncommon aceident, and that they seldom lighted a fire at night in a

By memory wounded, it is said, chamber, lest an incautious traveller should be found suffo

He licks his paws, and hangs his head. cated in his bed in the morning. If, however, precautions

How often lurks a treach'ruus sting be taken, by opening part of the door or window, and a

Under a specious covering. current of pure air be suffered to carry off the foul vapour,

False Gain, false Pleasure, weave a charm there is no danger.

For their base triumph, and thy harm. But why do people ever burn this dangerous substance ?

Be Truth and Virtue, then, thy choice, It has many good properties, and is very valuable in a

And list not to the Siren's voice, country where fuel is scarce. It is pure and clean, and has

Who, in the guise of seeining joy, not the dirty qualities of some English coal. It is diflicult

Would lure thee, chain thee, and destroy ! M. to light; but when once it is ignited, it burns with a very * For an account of the habits of this remarkable bird, see beautiful ruddy glow, which is communicated to the whole Sparrman's Travels in the Hottentot country; and Vol. V., page 112, mass, and has nothing of that obscure and dingy light of the Saturday Maguzine. which other coal gives out; the house within is never soiled with soot and ashes, and without, the air is clear, and Look about you, and see if three great idols, Honour, never loaded with those torrents of smoke which you see Pleasure, Gain, have not shared the earth amongst them, issuing from the chimneys, and darkening the air of other and left him least, whose all it is.—Bishor HALL. towns. Above all, the heat it gives out is intense; and so powerful, that it performs all the purposes for which fire is GRATITUDE is a species of justice. He that requites a used in houses in less time, and with a smaller quantity, benefit may be said, in some sense, to pay a debt; and, of than any other fuel,-insomuch so, that the good people course, he that forgets favours received may be accused of complain that it consumes even their grates and utensils neglecting to pay what he cannot be denied to owe.—DR. by its violence.—Dr. Walsp.

JOHNSON.

ON CROMLECHS.

judges, and arbiters of all differences both public The accompanying engraving exhibits a view of and private, and that they held an assembly every an insulated rock, popularly termed a Cromlech, year, at a certain place, in the middle of the country, standing on a moor in the parish of Constantine, in and consecrated for the purpose, where they took Cornwall, and called by the people of the country cognizance of murders, inheritances and boundaries, “ The Tolmen." The surrounding scene is wild in and decreed rewards and punishments. the extreme, the whole moor being thickly covered It is probable that this annual meeting took place with enormous blocks of granite, forming altogether at Stonehenge, and that inferior tribunals were held a subject worthy of the pencil of a Salvator Rosa. periodically in remote districts, where these stones

The origin of these rude monuments of ancient are found, and as has been before observed, they times is buried in the darkest obscurity, and must probably served as the presidial chair ; and as sacriconsequently be left entirely to conjecture, though fices were offered up at their religious assemblies, the all antiquaries appear to agree in attributing them victim was also slain upon them. There is a hollow to the Druids, but are much divided in their opinions of the diameter of about a foot and a half scooped as to the purposes for which they were erected, some out on the summit of the Tolmen, which might have supposing them to have been sacrificial altars, others, been intended as a receptacle for the blood as it again, considering them as monuments erected over flowed from the victim. the ashes of illustrious persons. The circumstance It is curious that the word “ Tolmen" may be of Kistvaens, or stone chests, having been discovered traced to the British words Toll, (the double II being under some of them, favours this latter opinion. pronounced as lth,) tribute, and Maen, a stone, from Mr. Rowland, in his Mona Antiqua, is inclined to whence a question would arise worthy the consideraconsider them as intended for purposes of sacrifice, tion of antiquaries ; Did the Druids receive tribute and supposes the word Cromlech to be derived from from the people? And if so, was it received as dues the Hebrew compound curamluach, a devoted stone, belonging to them as a priesthood, or ministers of or altar; that he should have had recourse to the religion? Hebrew for a derivation is extraordinary, the British What most fully establishes the hypothesis that word itself being so significant; for Krwm, in that these monuments are the works of the Druids, is language, is crooked or inclining, and Llech is a the fact, that they are found only in those countries stone, and the superincumbent stone, or roof of where Druidism prevailed, namely, in Gaul, Gerthese monuments, is always in a slanting position, many, and Britain, its chief seat in the latter in a greater or lesser degree; that of the Tolmen country being the Isle of Anglesey, the ancient inclines very little. It is not improbable but that Mona. they might have been used for both the above. The “Tolmen" points due north and south, is 33 mentioned purposes, and also as the presidial chair, feet in length, 18 feet in width in the widest part, and or seat of the chief Druid at their grand national 14 feet 6 inches in depth, 97 feet in circumference, assemblies.

and is calculated by admeasurement, to contain 750 We learn from Cæsar that the Druids were the tons of stone.

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LONDON: Published by JOHN WILLIAM PARKER, WEST STRAND; and sold by all Booksellers.

THE

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UNDER THE DIRECTION OF THE COMMITTEE OF GENERAL LITERATURE AND EDUCATION,

APPOINTED BY THE SOCIETY FOR PROMOTING CHRISTIAN KNOWLEI)GE.

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