of holding 440 gallons, lined with lead, and heated by steam, which is conveyed directly into the vat by means of a circular tube pierced with holes; when the tallow is melted, about 132 gallons of a solution of lime, containing about 120 lbs. of quicklime, is added, and the mixture is continually stirred. After six or seven hours, the saponification is terminated, and the soap of lime has formed a consistent mass, which becomes very hard on cooling. It is next reduced to a very fine powder, and decomposed by sulphuric acid, diluted with water, in vats similar to the first, and heated by steam; when the fatty acids being set free, form an oily stratum on the surface of the acid liquids. The melted fat is decanted, and washed several times, while hot, with water charged with sulphuric acid, and then with fresh water; it is finally run into tin moulds forming cakes of 6 or 8 lbs. in weight. This mass, which is still a mixture of stearic, margaric, and oleic acids, is first powerfully compressed when cold by the hydraulic press, in order to express the greater part of the oleic acid, and then compressed, when at a temperature of 90° or 100°, in order to drive out the remainder. The oleic acid thus expressed is of a deep brown colour, and contains nearly all the margaric acid, with a certain quantity of the stearic acid. The cakes remaining after this compression are again melted, in contact with a dilute solution of sulphuric acid, which removes the last traces of lime from the fatty substance; after which it is freed from the adhering acid by washing it in boiling water. It is then poured into moulds, where it becomes solid, and it is thus brought into commerce,as refined stearic acid, used for the manufacture of stearic lights. In the first process of making stearic lights, the wicks, twisted like those of the common wax-lights, became charred in the same manner as the wick of a candle, and required to be snuffed every minute. M. Jules Cambacérès substituted plaited wicks for twisted ones, and this fortunate invention was completely successful. In consequence of the plaiting, the wick in proportion as the light burned was turned and slightly bent downwards, so that the extremity was made to

consume itself in the flame.

Oil-lights.-Among the ancients, lamps were varied in form and matter. They were made of terra-cotta, bronze, silver, and even of gold. They had one or more wicks; and Suidas gave to a lamp the name of icosymica, because that it had twenty wicks. Still they were all constructed on the same plan. They were vessels in the form generally of an oblong cup, furnished with a gutter or spout, over the lip of which projected the extremity of a round wick placed in the vessel and lying soaked in the oil. These lamps were smoky and spread a disagreeable smell around them. It was by the light of such a lamp that Demosthenes composed those sublime orations which his enemies said smelt of the oil. The wick was regularly charred after a certain time, and it was necessary to trim it, because the level of the oil in the vessel was continually lowered by the combustion. Fig. 232 represents a Fig. 232.

the periodical action of the compression, the proper level of the oil is constantly restored. An apparatus, long known under the name of Mariotte's vessel, at last furnished the means of keeping the level of a running liquid at a constant Fig. 233,

height. The chemist Proust appears to have been the first who, towards the end of the last century, applied the idea of Mariotte's vessel to the reservoir of a lamp with a constant level. Fig. 234 represents one of the forms which has been Fig. 234.

given to this reservoir. The stop-cock at the bottom being shut, the cork at the top is removed and the reservoir filled; then the cork is replaced. When the lamp is to be lighted, the stop-cock below is opened, the oil rises in the shorter branch to the left, and supplies the wick; but it does not rise in this branch above the lower level of the open tube immersed in the reservoir. In proportion as the oil is consumed, the level sinks in the reservoir, and the vacuum thus formed is filled with the air which enters at the bottom of the open tube, and rises in bubbles through the liquid, but the level in the shorter branch remains constantly the same.

The lamp furnished with the side reservoir furnished with a flat wick, where the combustion operated in a much better manner than in the thick irregular wicks of the ancient lamps, was a very great improvement, especially when the wick was surrounded with a glass chimney. By means of the latter addition, a current of air was established which continually kept up the flame and guarded it from the wavering motions produced by the exterior air. Thus surrounded, the flame gave out a much more vivid light, and was prevented from smoking. It was reserved, however, for Argand to carry this arrangement to the highest degree of perfection, by inventing a burner with a cylindrical wick and a double current of air. The new current of air is produced in the centre or axis of the wick, and rises from the bottom of the wick-case. The invention of this burner, called the Argand burner, was first announced in February, 1784. It is the union of the constant specimen of an antique lamp. The ancients found that this level of Proust with the burner of Argand which forms the mode of lighting was susceptible of improvement, and they wall lamps manufactured on the great scale by Quinquet, and invented a variety of ingenious arrangements, of which the known by the name of the manufacturer. For hall lamps, or description has been transmitted to us in the writings of the suspensory lamps in general, the lateral reservoir was uncelebrated Hero, of Alexandria, who flourished at the end of sightly and inconvenient by reason of the shadow which it the second century B.C. Cardan, who died in 1575, gives a projected. To remedy this inconvenience, shadowless lamps description of a mechanical lamp analogous to that of Hero. were invented, having the reservoir in a circular form round It appears that these various kinds of lamps were very little the burner, and carrying an unpolished lamp-glass of a gloin use, since the authors referred to only speak of them as bular shape, which, by its effect, completely neutralised the objects of curiosity. shadow of the reservoir and conduits. If we substitute, for Towards the end of the last century, the pump or spring- the unpolished lamp-glass, a metal reflector, we shall have the lamp, in common use, was a great improvement on the ancient astral lamp of Bordier-Marcet. In the astral and shadowless lamp; see fig. 233. The upper part of this lamp is moveable, lamps the constancy of the level is not perfect, and the intenand can be made to descend into the reservoir by compressing sity of the light always decreases in proportion as the level of a spring; it is sufficient to exert this compression to make the the oil is lowered. Lamps also have been invented hav oil rise in the reservoir from above and soak the wick. By the reservoir situated above the burner. and furnishing

superabundance of ai u the wick antis was completely exhansted. This has been accompushed in inferent principles by MM. Carcei, Grant, and Tiener, mi by many other sucresting aventurs.

On account of this diminution of pressure, however, and the precautions required in its management, Thilorier's lamp has been almost laid aside for mechanical lamps; especially as the latter can be had at very low prices.

Carees, a watchmaker, nis non, paced at the lower Some years ago, under the name of the Solar lamp, an ingepart it a mini-cune amp, a string namism, by means nous apparatus for illumination was invented, in which, withof which a smal rang-pane rastity used the to out mechanism of any description, and even with inferior oils se the apper part of the Vis Busarer that the nse or grease, a flame of perfect whiteness was obtained. The should be regular, wo jumps wees, steast one reservoir of oil in this lamp widens towards the top, and pump wita ட்பர். Ir a desert of compressed a carnes in the middle, at its upper part, a burner, into which acting against a spring. Wit Sten. Sarten Cire the wick is immersed nearly to the level of the liquid; and have successive nude, movements m sing i though the burner has a double current of air, the combustion ons he ganton Gras amps on would not be long in becoming very imperfect, in consequence peme a Surs Suntun, bed nf the lowering of the level of the oil in the reservoir. But 245 fhs 11 am 2 per se. The the canney support being arranged as shown in fig. 236, the In a Chicera grei is Fig. 235.

constructed on this prone that it two men vating
Vessels are filled with liquids of diferent densities and these
liquids be in equilibrium, the heights of the liquids will be to
each other in the inverse ratio of their densities A solution
of sulphate of sin, properly prepared, having a considerably
greater density than that of all, not acting on the metal which
ntams fi, exerting no chemical action on the oil, and sup.
ating the varrations of temperature without sensible altera-
, was tually employed by M Thilorier in the construction
f his lamp with complete success, after many others had
tailed in the same attempt. In the above engraving, the place
of the sulphate of sino is indicated by the deeper shading, and
that of the oil by the lighter shading; the latter being pressed
by a denser liquid, rises up to the burner at a higher level
than that of the reservoir. In proportion as the level in the
latter is lowered, the pressure on the ascending column dimi-
nishes, but the air entering below the sulphate of zino, as in
Mariotto'a vessel, partly replaces the effect of this pressure,

tune undergoes, a little above the wick, a contraction in ward it as necessarily mixed with air, in the same way as in STAV VESIng apparatus. Thus it is elongated, and then sing considerably above the level of the oil, gives out an extremely nnd light. By this artifice, the carbonaceous parts set completely burnt, and which give to the flame a reddish nt are entirely consumed, and the light is rendered perSectly clear.

Zyla marivas Aids-The oils of turpentine, naphtha, and petroleum, the essential oils extracted from schists, tar, cases and resins, being composed, like common oil, of carbon And hydrogen, although in different proportions, it was natural to endeavour to employ them in illumination; but it was impossible to burn them in the apparatus adapted for oilghts, because the excess of carbon they contain rendered them too smoky to be borne. In order to obtain a proper aght, different means must be employed; thus, highly carSuretted ous must be mixed with other liquids which are but slightly carburetted, in order to compensate the excess of car

in the one by the want of it in the other; next, to supply the flame which they produce with a sufficient quantity of air, so that the excess of carbon may not escape combustion, and form lamp-black; but, on the contrary, may burn in the dame, by combination with the oxygen of the air, when the air is abundantly supplied. The vaporization of the burning liquid powerfully assists these two methods of rendering the above-mentioned fluids available.

a

In 1882, a system of lighting, conducted on these principles, was introduced into France. The matter employed was known under the name of liquid gas, liquid hydrogen, or gazogen. As liquid slightly carburetted for the preceding mixture, alcohol, methylic alcohol (spirit of wood), or ether, has been employed; and the name alcoholate has been proposed for the mixture itself. Recently, however, unmixed essential oils have been employed for illumination, and by means of very ingenious arrangements, very perfect combustion has been obtained, and a flame almost without smoke. M. Gaudin has invented an artificial light by directing a current of air upon a jet of some essential oil, and producing a powerful action at its extremity, by throwing it on a ball of quicklime prepared in a particular manner. He has thus produced the combustion of the oil of

turpentine without smoke, and obtained a flame of which the whiteness far surpasses that of a Carcel lamp. With pure oxygen, the flame became of a dazzling white, and gave a light 150 times greater than oil-gas.

Drummond-light.-The application of the oxyhydrogen blowpipe for purposes of illumination, by throwing an ignited jet of the mixture of oxygen and hydrogen upon a cylinder of lime, is well known under the name of the Drummond light. In this case, the nozzle or orifice of the blowpipe must be pointed upwards, in order to allow the flame to play upon the lime.. In all practical applications of the oxyhydrogen blowpipe, the plan of employing the gases mixed beforehand in the reservoirs has been abandoned, and the original plan of the inventor, Dr. Hare, has been again adopted. The gases are generally kept in metallic reservoirs, and their regular and steady efflux is effected by hydrostatic pressure and stopcocks immersing the gasometers or reservoirs in water. For larger purposes, closed reservoirs may, in large cities, where such conveniences present themselves, be connected by a pipe and stop-cock with the pressure of the city water-works. The hydrogen may in many cases be employed as obtained directly from a large self-regulating reservoir, containing zinc and dilute sulphuric acid. The facility with which large india-rubber bags are now manufactured, and the convenience and nicety with which they are filled with the gases, and these, in like manner, retained and subsequently discharged by superposed weights, has lately introduced them into extensive use for the purposes above-mentioned. From the reservoirs, the gases are delivered by pipes furnished with stop-cocks, at the orifices where the combustion takes place. Near these, the pipes are either made to combine by being united into one, as the two branches of the letter y; or the

pipe with the oxygen terminates concentrically within the pipe discharging the hydrogen, likewise at, or a short distance inside of, its terminating orifice. Just before the union of the two discharge-pipes, these may be furnished with inserted safety-pipes, consisting of a number of tubes with small boxes, or containing a series of wire-gauzes. The gases may also, after their mixture, and before being discharged through the orifices, be conducted through a similar safety-tube; but these safety-tubes are often dispensed with, as, with the proper precautions of always keeping the gases under sufficient pressure during their use, and attending to the closing of the stop-cocks when not in use, no danger of the return and the mixture of the gases, and the consequent explosion, need be apprehended.

Gas-light. While oil-lights were gradually reaching a
more perfect state, a substitute for them on a large scale was
invented about the beginning of the present century. In
1785, attempts had been made in France, by Lebon, to produce
gas-light by the distillation of wood. Mr. Murdoch (whose
experiments began in 1792) introduced coal gas, as a mode of
and Watt, at Soho, near Birmingham, and into the cotton
illumination, in 1805, into the workshops of Messrs. Boulton
factory of Messrs. Phillips and Lee, at Manchester. In 1815
the same mode of lighting factories was introduced into
France by Mr. Winsor; but it was not till some years after
this period that the scheme succeeded in that country.
The illuminating gas is chiefly composed of carburetted
hydrogen, of which the density is 0.6 of that of air, and is
obtained by the destructive or dry distillation of coal. The
following table will give our readers an idea of the products
arising from this process.

Residue: Coke, consisting of carbon and earthy matter.

For

The best coal for making illuminating gas is considered to by the distillation of bituminous coal, is composed chiefly of
be that known by the name of bituminous or fatty coal, burn- protocarburetted hydrogen, carbonic oxide, carbonic acid, nitro-
ing with a long flame; some kinds yielding upwards of 8,000 gen, oleaginous matters more or less easily condensed, ammo-
cubic feet of gas per ton of coals: but that kind of coal called niacal and sulphuretted compounds, and tarry substances.
cannel coal yields from 10,000 to 12,000 cubic feet of gas per As in this state the gas exhales a very fetid smell, and the
ton. The distillation is effected in large cylindrical cast-iron products of the combustion are themselves odoriferous, it is
retorts, ranged parallel to each other, to the number of three necessary to purify the gas, especially for domestic use.
or five, over the same furnace; each retort being provided this purpose it is conveyed from the retort into a small barrel,
with a vertical tube, through which the coal is introduced, partly filled with water, through a pipe entering into the
and to which the pipe is fastened for the discharge of the gas. liquid about one-eighth or a quarter of an inch, so as to inter-
The temperature of the furnace must be kept at a bright cept the communication of the retort with the apparatus in
cherry-red heat, because if it be greater, the gas does not which the gas is collected. The greater part of the water and
give so much light; for the bicarburetted hydrogen gas and tar condenses in the barrel, which is furnished with a dis-
the very volatile oils, to which the brilliancy of the flame is charging pipe to maintain a constant level in the barrel, and
chiefly owing, deposit carbon, and are converted into proto- to allow the excess of the condensed products to escape. The
carburetted hydrogen, the combustion of which gives but gas, on leaving the barrel, traverses a series of pipes more or
little light; and if, on the contrary, the temperature be too less cooled, in which the condensation of the water and tar
low, a large quantity of essential oil is formed, which cannot is completed, and is then conducted through boxes containing
remain in suspension in the gas, but is deposited in the refri- metallic salts, chiefly chloride of manganese and sulphate of
gerators. The duration of the distillation varies according to iron, which decompose the ammoniacal salts and isolate the
the quality of the coal, its hygrometric state, and the arrange-sulfhydric acid; finally, it passes through other boxes con
ment of the apparatus; and the residue consists of a light taining hydrated lime, which absorbs the sulfhydric gas, the
coke, much used for domesti: purposes. The gas produced carbonic acid and the other acid vapours. But these purifi

exterior appearance of the gas-meter. The gas enters at B and goes out at A.

The pipes which conduct the gas may be made of cast-iron, stone-ware, iron-plate, covered with bituminous mastic, gal. vanized iron-plate lead, or zinc. The burners have generally the form of those of Argand's lamp, in order that they may have the double current of air. This burner is pierced with fifteen or twenty holes of about one-twentieth of an inch or less in diameter, the diameter of its central space being rather less than an inch.

morning and find myself dead," to make a fire as speedily as
possible. I now first perceived that, in my very natural hurry
to escape from my shaggy foe, I had lost the martin-skin
wherein I carried my flint, steel, and tinder. This was of
little consequence; I had often made a fire by the aid of my
gun before, and I drew my knife and began to pick the flint.
Death to my hopes-at the very first blow I struck it ten
yards from the lock, and it was lost for ever in the snow.
"Well," said I to myself, "I have cooked a pretty kettle
of fish, and brought my calf's head to a fine market. Shall
I furnish those dissectors, the wolves, with a subject, or shall
cold work the same effect on me that grief did upon Niobe?
Would that I had a skin like a buffalo!

Necessity is the spur, as well as the mother, of invention; and, at these last words, a new idea flashed through my brain like lightning. I verily believe that I took off the skin of my victim in fewer than ten strokes of my knife. Such a hide entire is no trifle; it takes a strong man to lift it;-but I rolled the one in question about me, with the hair inward, and lay down to sleep, tolerably sure that neither Jack Frost nor the wolves could get at me, through an armour thicker and tougher than the sevenfold shield of Ajax.

Darkness closed in; and a raven began to sound his note of evil omen from a neighbouring branch. "Croak on, black angel," said I; "I have heard croaking before now, and am not to be frightened by any of your colour." Suddenly a herd of wolves struck up at a distance, probably excited by the scent of the slain buffalo. "Howl on," said I; "and, being among wolves, I will howl too-for I like to be in the fashion: but that shall be the extent of our intimacy." Accordingly, I uplifted my voice, like a pelican in the wilderness, and gave them back their noise, with interest. Then I lay down again, and moralised. This, thought I, is life. What would my poor mother say, if she were alive now? I have read books of adventure, but never read anything like this. I fell asleep, without further ado.-Sneling.

THOUGHTS ON POLITENESS.

The common notion about politeness is, that it is a thing of the body, and not of the mind; and that he is a polite man who makes certain motions in a graceful manner, and at proper times and places. We expect the dancing master to teach our children "manners," as well as the art of cutting awkward capers to music. But the truth is, that we degrade politeness by making it anything less than a cardinal virtue.

The happiness of life is made up of an infinite number of little things, and not of startling events and great emotions; and he who daily and hourly diffuses pleasure around him by kind offices, frank salutations, and cheerful looks, deserves as well of his species, as he who, neglecting or despising all these, makes up for it by occasional acts of generosity, justice, or benevolence. Besides, the opportunity of doing great things but rarely occurs, while a.man has some dozens of chances, every day of his life, to show whether he be polite

or not.

A truly polite man must, in the first place, have the gift of good sense, for, without that foundation, it is idle to think of rearing any, even the smallest superstructure. He must know when to violate that code of conventional forms which common consent has established, and when not; for it is equally a mark of weakness to be a slave to these forms or to despise them. He must have penetration and tact enough to adapt his conversation and manner to circumstances and individuals; for that which is politeness in the drawing-room, may be downright rudeness in the bar-room or the stage-coach, as well

as the converse.

Above all, he must have that enlarged and catholic spirit of | humility, which is the child of self-knowledge, and the parent of benevolence (indeed, politeness itself is merely benevolence seen through the little end of a spy-glass), which, not content with bowing low to this rich man. or. that fine lady, respects the rights, and does justice to the claims, of every member of the great human family.

As for the fastidious and exclusive persons, who look down upon a man created and upheld by the same power as themselves, and heir to the same immortal destinies, because he does not dress in a particular style, or visit in certain houses, they are out of the question. If they are too weak to perceive

the grotesque absurdity of their own conduct, they have not capacity enough to master the alphabet of good manners. If angelic natures be susceptible of ludicrous emotions, we know of nothing more likely to call them forth than the sight of an insect inhabitant of this great ant-hill assuming airs of superiority over his brother emmet, because he has a few more grains of barley in his granary, or some other equally cogent

reason.

Of the gentlemen, young and old, whiskered and unwhiskered, that may be seen in Regent-street any sunshiny day, there is not one who does not think himself a polite man, and who would not very much resent any insinuation to the contrary. Their opinion is grounded on reasons something like the following. When they go to a party, they make a low bow to the mistress of the house, and then look round for somebody that is young and pretty to make themselves agreeable to.

At a ball they will do their utmost to entertain their partner, unless the fates have given them to some one who is ugly and awkward; and they will listen to her remarks with their most bland expression. If they are invited to a dinner party, they go in their best coats, praise their entertainer's wine, and tell the lady they hope her children are all well. If they tread on the toes of a well-dressed person, they will beg his pardon. They never spit on a carpet; and, in walking with a lady, they always give her the inside; and, if the practice be allowable, they offer her their arm.

So far, very good; but I must always see a man in certain situations before I decide whether he be polite or not. I should like to see how he would act if placed at dinner between an ancient maiden lady and a country clergyman with a small salary and a rusty coat, and with some distinguished person opposite to him. I want to see him on a hot and dusty day, sitting on the back seat of a stage-coach, when the driver takes in some poor lone woman, with, may be, a child in her arms, and tells the gentlemen that one of them must ride outside and make room for her.

I want to be near him when his washerwoman makes some very good excuse to him for not bringing home his clothes at the usual time, or not doing up an article in exactly the style he wished. I want to hear the tone and emphasis with which he gives orders to servants in steam-boats and taverns, I mark his conduct when he is walking with an umbrella, on a rainy day, and overtakes an old man, or an invalid, or a decent-looking woman, who are exposed, without protection, to the violence of the storm. If he be in company with those whom he thinks his inferiors, I listen to hear if his conversation be entirely about himself. If some of the number be very distinguished, and some quite unknown, I observe whether he acts as if he were utterly unconscious of the presence of these last.

These are a few, and but a few, of the tests by which I try a man; and, I am sorry to say, there are very few who can stand them all. There is many a one who passes in the world for a well-bred man, because he knows when to bow and smile, that is down in my tablets for a selfish, vulgar, unpolite monster, that loves his own little finger better than his neighbour's whole body. Put any man in a situation where he is called upon to make a sacrifice of his own comfort and ease, without any equivalent in return, and you will learn the difference between true politeness, that sterling ore of the heart, and the counterfeit imitation of it, which passes current in drawing-rooms. Any man must be an idiot not to be polite in society, so called; for how else would he get his oysters and champagne?-Hillard.

ODE ON ART

When, from the sacred garden driven,
Man fled before his Maker's wrath,
An angel left her place in heaven,

And crossed the wanderer's sunless path.
'Twas Art! sweet Art! new radiance broke
Where her light foot flew o'er the ground;
And thus with seraph voice she spoke,-

"The Curse a Blessing shall be found."
She led him through the trackless wild,
Where noontide sunbeam never blazed;