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PRACTICAL SCIENCE.

GLASS-WORKING.
(Continued from page 40.)

9. Soldering. When the tubes to be soldered are of the same diameter and thickness, they should be heated at the points of junction, and the edges slightly turned out by means of a piece of iron wire, as directed § 7. When the two parts are bordered, heat them both to a cherry red heat, and join them together just as they fuse, taking care not to use too much force, and to maintain the heat until the two tubes are cemented or soldered together. A little practice will soon enable you to accomplish this operation neatly and quickly; but you will always distinguish the part where they have been soldered.

In soldering tubes or glass of any description, be sure always to unite two of the same kind, otherwise the joint is liable to give way as it cools, on account of the irregular contraction of the glass.

When a tube requires to be soldered to the side of another, it becomes necessary to draw out the one tube, and then having cut off the superfluous part, bordered it, and heated the edges to a cherryred heat, the other tube is to be bordered and soldered to the first, as directed above, and shown in the accompanying figure. When the soldering is effected, warm the point of junction until it becomes perfectly soft, and then blow gently into the tube, so as to make the softened part bulge out; then work it gently backwards and forwards, until the surface becomes almost uniform. Sometimes it is necessary to solder a small piece of glass over a hole in some vessel. When this is the case, proceed thus dry the vessel well, then fuse the part to be soldered; and having heated a piece of glass to a cherry-red heat, lay it upon the part, and heat until they fuse together.

10. Piercing. It is necessary sometimes pierce a tube or other vessel, but parti

Fig. 1.

cularly the former; this is often done for the purpose of joining another tube to it. When you wish to pierce a tube, seal one end (§ 14), then, closing the other end with your finger, direct the flame of the blow-pipe upon the part you wish to pierce, and maintain a reddish white heat until the air within expands with the heat, and bursts a hole through the softened glass. Sometimes, especially if the tube is long, or the vessel large, the hole is made by blowing forcibly into the vessel, when the glass has become heated to a reddish white.

When the tube has been pierced, it becomes necessary to submit it again to the influence of the blow-pipe flame, in order to border the edges, and prepare it for soldering.

11. Choking is not the actual closing or stopping of a tube, but the contraction of its diameter, like the part between a and bin § 8, p. 40. This operation is performed by heating the part to be choked to a cherry-red heat, and then gently drawing it out until the tube is sufficiently choked. To make a fine glass funnel. Select a

tube of the proper diameter and proceed to draw out one part of it as directed in § 8, p. 40; but take care to do this gradually, so as to make the part drawn out assume the form of a fine tube, as in the annexed figure; when the proper length for the neck of the funnel has been obtained, cut off the irregular part, when the glass has cooled Fig. 2. down. It now only remains to border the upper part in the manner directed in § 7, p. 40.

13. To enlarge the diameter of a tube. It is sometimes necessary to enlarge the diameter of a tube at one end, and when this is required, you must heat the part to be widened in the flame of a spirit-lamp, and when it is soft, insert a stout piece of warm iron wire, and work it round and round with a firm and even pressure, the same as if you were bordering the tube; but observing that the iron rod is introduced further into the tube than when bordering. The operation of widening must be repeated over and over again, until the tube is sufficiently enlarged.

14. Sealing. We have frequently to

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Sometimes it is requisite that the end of the tube when sealed should be flat; when this is the case, it must be pressed while soft against a flat surface. If the end is to be concave, like the bottom of a wine bottle, force the centre of it inwards with an iron wire while it is quite soft.

15. Glass-blowing requires great care and frequent practice, being one of the nicest operations connected with glass-working.

It is usual to commence glass-blowing by sealing a tube and blowing a bulb at the end of it. This is done by thickening the end of the tube during the operation sealing, and after it is heated to a reddish white heat, removing it from the flame and holding it horizontally while you blow quickly and strongly into the tube, turning it rapidly round at the same time. If the bulb is not large enough, heat it again, and repeat the operation until it has acquired the requisite size, taking care to keep your eye fixed upon the bulb so that you may leave off blowing immediately it has dilated to the size you wish. You should not try to blow the bulb at once, but gradually. If you wish to have a somewhat flattened bulb, hold the tube upright while blowing, and if you wish to have it pyriform or pearshaped let the heated end depend.

It is sometimes required to have a bulb in the middle of the tube, and this may be formed by either of the following methods: 1st, by sealing one end of the tube, then drawing out the other and sealing that, so

as to enclose some atmospheric air, and afterwards heating the part to be dilated. The atmospheric air enclosed within the tube expands by the heat and causes the tube to swell out at the part where it is rendered soft by the heat. 2nd, by blowing a bulb and afterwards soldering (§ 9) both ends of it to two tubes as shown, in Fig. 3.

Fig. 3.

16. To make a dropping tube. - First choose a tube that is narrower at one end than the other, then seal the narrow end and thicken it in the flame of a spirit-lamp by fusion. When heated to a cherry red, blow the bulb and afterwards draw out a point from it (§ 8, p. 40). If the point drawn out is not long enough, solder a narrow piece of tubing to the bulb, and draw out the end of the tube afterwards.

This forms a useful instrument for applying small tests, by adding one or more drops of a fluid to a tube or glass of the liquid to be tested.

Fig. 4.

THE LITERATURE OF THE AGE OF ELIZABETH.-The age of Elizabeth was distinguished beyond, perhaps, any other in our history, by a number of great men, famous in different ways, and whose names have come down to us with unblemished honours statesmen, warriors, divines, scholars, poets, and philosophers; Raleigh, Drake, Coke, Hooker, and higher and more sounding still, and still more frequent in our mouths, Shakspere, Spenser, Sidney, Bacon, Jonson, Beaumont and Fletcher-men whom fame has eternized in her long and lasting scroll, and who, by their words and acts, were benefactors of their country, and ornaments of human nature. Their attainments of different kinds bore the same general stamp, and it was sterling; what they did had the mark of their age and country upon it. Perhaps the genius of Great Britain (if I may so speak without offence or flattery) never shone out fuller or brighter, than at this period.-Hazlitt.

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IN the manufacture of hats of every description, exclusive of straw, there are more than 20,000 persons employed; and, besides those consumed at home, between fifty and sixty thousand dozens are annually exported to the British colonies and the Brazils, the value of which has been estimated at about £130,000; whilst the value of all the hats manufactured annually at the principal marts, namely, London, Manchester, Glasgow, Liverpool, &c., &c., is little under two millions and a half, a prodigious sum expended for one single article of dress.

SACRED QUOTATIONS.

FLOWERS.

THE plants look up to heaven, from whence SHAKSPERE. They have their nourishment.

To me the meanest flower that blows, can give Thoughts that do often lie too deep for tears. WORDSWORTH.

FOSTER the good, and thou shalt tend the flower
Already sown on earth :-

Foster the beautiful, and every hour
Thou call'st new flowers to birth.

YE are the Scriptures of the earth,
Sweet flowers fair and frail;
A sermon speaks in every bud
That woos the summer gale.

SCHILLER.

Defying stormy hours; Ye are like fearless faith, O precious winter flowers.

ANONYMOUS.

THERE is a lesson in each flower,
A story in each stream and bower;
On every herb on which you tread
Are written words which, rightly read,
Will lead you from earth's fragrant sod,
To hope, and holiness, and God.
ALLAN CUNNINGHAM.
PALE winter flowers! the clouds aloft
The sunless skies deform,-

How can ye spread your blossoms soft
To face the pelting storm?
Ye have a root beneath,

MISS M. A. BROWNE, THE sickliest leaf, The feeblest efflorescence of the moss, That drinks thy dew, reproves our unbelief. The frail fleld-lily, which no florist's eye Regards, doth win a garniture from thee To kings denied. So while to dust we bow Needy and poor, oh, bid us learn the lore Graved on the lily's leaf, as fair and clear As on yon disk of fire-to trust in thee. MRS. SIGOURNEY.

THE enlivening sap, Obedient to Thy laws, through fitted tubes Ascends fermenting, and, at length matured, Breaks forth in gems, and germinates in leaves. By thee each family of flowers is clothed In one unvarying dress, and breathes the same Transmitted essences; and though the loom No virgin-fingers ply to swell her pride, The lily shines, more gorgeously array'd Than monarchs, where the East, with hand profuse,

Showers on their pomp barbaric pearl and gold. SMART.

OBSERVE the rising lily's snowy grace,
Observe the various vegetable race;
They neither toil nor spin, but careless grow,
Yet see, how warm they blush! how bright
they glow!
What regal vestments can with them compare i
What king so shining! or what queen so fair!
If ceaseless thus the fowls of heaven He feeds,
If o'er the earth such lucid robes he spreads;
Will He not care for you, ye faithless, say?
Is He unwise?-or are ye less than they?

THOMPSON

RUDIMENTS OF COOKERY.

(Concluded from page 179.)

VEGETABLES and meat are sometimes steamed: that is, they are put into vessels resembling cullenders, and being placed over boiling water, the steam from it rises through the holes of the vessel, and then through the vegetables and ineat, which are thus as effectually boiled as if they were put into the boiling water.

Roasting. The success of every branch of eookery depends upon the good management of the kitchen fire: roasting, especially, requires a brisk, clear, and steady fire; if made up close to the bars of the grate.

The spit being wiped clean, the joint to be roasted should be carefully spitted even, and tied tight; and if it will not turn round well, balance skewers, with leaden heads, should be used; for, if the meat be not evenly spitted, it will probably be burned on one side, and not done on the other. Avoid running the spit through the prime parts of joints. Cradle spits answer best.

A leg of mutton should never be spitted, as the spit lets out the gravy, and leaves an unsightly perforation just as you are cutting into the pope's eye.

Make up the roasting-fire three or four inches longer than the joint, else the ends of the meat will not be done.

In stirring the fire, be careful to remove the dripping-pan, else dust and ashes may fall in. On no account let the fire get dull and low, as a strong heat is requisite to brown the meat.

A thin joint requires a brisk fire; a large joint, a strong, sound, and even fire. When steam rises from the neat, it is done.

Large joints should be put at a moderate distance from the fire, and gradually brought hearer; else the meat will be overdone halfway through the joint, and be nearly raw at the bone.

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tinually changing: the age and size (especially the thickness) of the pieces, the quality of the coals, the weather, the currents of air in the kitchen, the more or less attention of the cook, and the time of serving, are all to be considered. Hence, epicures say of a well-roasted joint, "It is done to a turn."

Roast meats should be sent to table the moment they are ready, if they are to be eaten in perfection.

Broiling.-Broiling requires a brisk and clear fire, proportioned to the article to be broiled; for example; mutton chops require a clear rather than a brisk fire, else the fat will be wasted before the lean is warmed through; but for a beef steak, the fire can neither be too brisk nor clear, if the gridiron be placed at the proper distance. Fish requires a steady fire; as also does under-done meat.

Much, however, depends on the substance of the article to be broiled: if it be thick, it must be placed at a greater distance, at first, to warm it through; if thin, the fire must be brisk, else the meat will not be of a good colour.

The gridiron should be wiped clean after it has been used, so that the bars may be kept bright on top; they should be allowed to get hot before the article is laid on them, but not too hot, else they will burn the meat or fish: the latter, especially. To prevent this, the bars should be rubbed with fat.

A charcoal fire is best for broiling.

To prevent the fat dripping into the fire set the gridiron aslant.

For turning the broiling article, use tongs, as a fork will let out the gravy. When the article is done, it will feel firm if touched with the tongs: by no means cut the meat to ascertain if it be done, as that will let out the gravy.

Frying-is "to scorch something solid in fat, or oil, or butter. Lard, clarified suet, ΟΙ dripping, is well adapted for fish, eggs, potatoes, and meat generally. Olive oil is much used for fish; and the same oil will serve for more than one frying. Butter is used, but it is not as well adapted for frying as either of the other articles.

Be careful that the fat or oil is fresh, clean, and free from salt, else what you fry in it will be of bad colour and flavour; salt will prevent it from browning.

Fat or oil, to be used again, should be strained through a sieve before it is set aside.

Fat becomes richer from having meat fried into it, and may be used repeatedly; but the fat that has been used for fish cannot be used again for meat.

The fat must have left off bubbling and be quite still before you put in the articles.

To prepare crumbs for frying, dry thoroughly in a warm oven, or before the fire, any waste pieces of bread; then pound them in a mortar and sift them, and put them away till wanted. This is much better than grating bread as it is needed, or using oatmeal, &c.

When you wish fried things to look as well as possible, do them twice over with egg and crumbs.

If eggs be very dear, a little flour and water may be substituted for them in preparing fish to fry.

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