THE WORK-TABLE FRIEND.

CHEESE DOYLEY, IN CROCHET. Materials.-Messrs. W. Evans and Co.'s Boar'shead crochet cotton, No. 24. Crochet hook, No. 20.

MAKE a chain of eight stitches, close it into a round, and work three rounds of Sc, increasing always sufficiently to keep the work flat.

4th Round.-Dc, increasing as before. 5th Round. + 3 Dc in one, miss 1, +all round.

of 4 Dc, 3 Ch, 5 Dc, (over 3 De and one chain on each side), 3 Ch, + 12 times.

11th Rouna.+ 2 Dc on the centre one of 3 Dc, 3 Ch, 3 Dc, (over 1 Ch and 2 Dc, 2 Ch, miss centre one of 5 Dc, 3 Dc, 3 Ch), + 12 times.

12th Round.-+1 Dc, (over 1st of 2 Dc, 3 Ch, miss 3, 3 Dc, 4 Ch, miss 4, 3 Dc, 3 Ch, + 12 times.

13th Round.+ 1 De over 1 Dc, 3 Ch, miss 2, 5 Dc, 2 Ch, miss 2, 5 Dc, 3 Ch, + 12 times.

18th Round.+4 De over 1 Ch, and 3 of 7 Dc, 2 Ch, miss 1 Dc, 4 De over 3 De and 1 chain, 4 Ch, 9 Dc over centre 9 of 11, 4 Ch, + 12 times.

19th Round.-4 Dc, beginning on the last chain stitch before 4 Dc, 5 Ch, miss 2 Ch and 1 De on each side, 4 Ch, 7 Dc on centre 7 of 9, 4 Ch, + 12 times.

20th Round.+4 Dc as before, 4 Ch, 1 De on the centre of 5 Ch, 4 Ch, 4 Dc, (on the last 3 Dc, and a chain stitch beyond), 4 Ch, 5 Dc, 4 Ch, + 12 times.

21st Round.+4 Dc as before, 4 Ch, 4 De, (doing 2 on the 1 Dc of last round), 4 Ch, 4 Dc, 4 Ch, 3 Dc on centre of 5 Dc, 4 Ch, 12 times.

22nd Round. + 4 Dc, as before, 4 Ch, 8 Dc, (over 4 Dc, and one chain at each end,) 4 Dc, 4 Ch, 4 Dc 4 Ch, 1 De on centre of 3, 4 Ch, +12 times.

23rd Round. + 4 Dc as before, 4 Ch, 4 Dc, 3 Ch, miss the centre 2 of 8 Dc, 4 Dc, 4 Ch, 4 Dc, 3 Ch, 1 Dc, on 1 Dc, 3 Ch,+12 times.

24th Round.-+ 4 Dc as before, 4 Ch, 4 Dc, 6 Ch, (over 3 Ch, and 1 De, at each

times.

25th Round.+4 Dc, (beginning on the last of 5 Ch,) 5 Ch, miss 4, 4 Dc, 3 Ch, 2 Dc, (on centre 2 of 6 Ch,) 4 Dc, 5 Ch, 4 Dc, 3 Ch, + 12 times.

26th Round.+9 Dc, (coming over the last 3 Ch, and 3 Dc, on each side,) 4 Ch, miss 3, 1 De on centre of 5 Ch, 4 Ch, miss 3, 4 Dc, 6 Ch, 4 Dc, 4 Ch, miss 3, 1 Dc, 4 Ch, miss 3, + 12 times.

27th Round.-+7 Dc on centre 7 of 9 Dc, 4 Ch, 4 De on 1 Dc, and 1 chain at each side, 4 Ch, 4 Dc, 4 Ch, 4 Dc, 4 Ch, 4 Dc, over 1 Dc, and 1 Ch, at each side, 4 Ch, + 12 times.

28th Round.-+5 De over centre 5 of 7, 4 Ch, 7 Dc, (over 4 Dc and 1 Ch at each side,) 4 Ch, 10 Dc, over 4 Ch, and 3 Dc, at each side, 4 Ch, 7 De over 4 Dc, and 1 chain at each side, 4 Ch, +12 times.

29th Round. + 3 De, (over centre 3 of 5 Dc,) 4 Ch, 4 Dc, 2 Ch, miss centre one of 7 Dc, 4 Dc, 4 Ch, 9 De over centre 8 of 10 Dc, 4 Ch, 4 Dc, 2 Ch, miss centre 1 of 7 Ch, 4 Dc, 4 Ch, + 12 times.

30th Round.-+1 Dc, 4 Ch, 4 Dc,

4 Ch, 4 Dc, 4 Ch, 7 Dc, 4 Ch, 4 Dc, 4 Ch, 4 Dc, 4 Ch, + 12 times.

31st Round. 1 Dc, on 1 Dc, 3 Ch, 4 Dc, 3 Ch, 1 De, 3 Ch, 4 Dc, 4 Ch, 5 Dc, 4 Ch, 4 De, 3 Ch, 1 Dc, 3 Ch, 4 Dc, 3 Ch, 12 times.

4th Pattern Row-13 Sc on centre of 15, 5 Ch, 1 De on Dc, 2 Ch, 1 De on 1 Dc, * 4 times, 5 Ch, + repeat all round.

--

33rd Round. 4 Dc, (beginning on the 2nd of the last 4 Dc,) 3 Ch, (coming over the first 1 De, of last row, and 1 chain on each side,) 4 De, 3 Ch, 7 Dc (over 4 De and 1 chain on each side), 3 Ch, 4 Dc, 4 Ch, 1 Dc, 4 Ch, 4 Dc, 3 Ch, 7 Dc, (as former), 3 Ch, + 12 times.

34th Round. 9 De, beginning_on 2nd of the 1st 4 De, 3 Ch, miss 3, 9 Dc, (over 7 Dc, and 1 chain on each side,) 3 Ch, miss 3, 4 Dc, 7 Ch, (over 1 Dc, and 3 Ch on each side), 4 Dc, 3 Ch, miss 3,9 Dc, 3 Ch, miss 3, + 12 times.

35th Round. 5 De, beginning on the 3rd of the 1st 9 Dc, 4 Ch, miss 4, 11 Dc, 4 Ch, miss 4, 4 Dc, 3 Ch, miss 3, 4 Dc, 4 Ch, miss 4, 11 Dc, 4 Ch, miss 4, +12 times.

36th Round.+1 De, on the centre of 5 Dc, 5 Ch, miss 5, 13 Dc, 5 Ch, miss 57 Dc, (over 3 Ch, and 2 Dc, at each side,) 5 Ch, miss 5, 13 Dc, 5 Ch, miss 5, +12 times.

37th Round.+17 Dc, (over the last 13 De, and 2 Ch, on each side), 7 Ch, miss 7, 17 De, as before, 6 Ch, miss 6, 1 Dc, on the centre of 7 Dc, 6 Ch, miss 6, + 12 times.

This is the end of the round. The lace which follows is not only extremely suitable for doyleys generally, but also any edgings in which lightness and durability are essential. When used detached from the doyley, make a chain of any number of stitches, divisible by 28, and do on it a row of Sc.

1st Pattern Row. + 1 Dc, 1 Ch, miss 1 repeat all round.

2nd Pattern Row-17 Sc, 13 Ch, miss 10, repeat all round.

3rd Pattern Row. + 15 Sc, (over centre 15 of 17), 5 Ch, i De on the 5th Ch, * 1 Ch, miss none, 1 De, 4 times, 5 Ch, repeat all round.

7th Pattern Row.

7 Sc over 9, 5 Ch,

De on every De with 5 Ch between, 5 Ch, +repeat all round.

This pattern is engraved so that the design may be transferred from it to the muslin, using a solution of indigo with thin gum water, and a sable brush. All the parts marked with a cross are to be entirely cut out, after being traced round with not less than three thicknesses of cotton. They are then to be worked closely in button-hole stitch. The edge is also to be worked closely in button-hole stitch, graduated as in the engraving, and very much raised in order to give a thick and rich appearance to the edge.

The embroidery cotton is to be used for all this, and the Boar's-head cotton for the English lace.

THE EXPANSION OF SOLIDS.

DR. ARNOTT exemplifies by the following cases the expansive properties of solids.

He says: "A cannon-ball, when heated, cannot be made to enter an opening, through which when cold it passes readily. A glass stopper sticking fast in the neck of a bottle, often may be released by surrounding the neck with a cloth taken out of warm water, or by immersing the bottle in the water up to the neck; the binding ring is thus heated and expanded sooner than the stopper, and so becomes slack or loose upon it. Pipes for conveying hot water, steam, hot air, &c., if of considerable length, must have joinings that allow a degree of shortening and lengthening, otherwise a change of temperature may

destroy them.

An incompetent person undertook to warm a large manufactory by steam from one boiler. He laid a rigid main pipe along a passage, and opened lateral branches through holes into the several apartments, but on his first admitting the steam, the expansion of the main pipe tore it away from all its branches. In an iron railing, a gate which during a cold day may be loose and easily shut or opened, in a warm day may stick, owing to there being greater expansion of it and of the neighbouring railing, than of the earth on which they are placed. Thus also the centre of the arch of an iron bridge is higher in warm than in cold weather; while, on the contrary, in a suspension or chain bridge, the centre is lowered. The iron pillars now so much used to support the front walls of houses, of which the ground stories serve as shops with spacious windows, in warm weather really lifts up the wall which rests upon them, and in cold weather allows it to sink or subside-in a degree considerably greater than if the wall were brick from top to bottom. In some situations, as was seen in the beautiful steeple of Bow church, in London, where the stones of a building are held together by clamps or bars of iron, with their end bent into them, the expansion in summer of these clamps will force the stones apart sufficiently for dust or sandy particles to lodge between them; and then, on the return of winter, the stones, not being at liberty to close as before, will cause the ends of the shortened clamps to be drawn out, and the effect increasing with each revolving year, the structure will at last be loosened and may fall."

THE VENTILATION OF ROOMS,

LARGE HALLS, &c.

VENTILATION is not so difficult a matter as it is generally imagined; but for want of due consideration, many serious blunders are committed. 1. Where gas or oil is consumed for lighting a room, a large amount of carbonic acid and water is generated, and this takes place in every room where we have even candles. Now, the result is this-the hydrogen of the gas, or oil, or tallow, unites with the oxygen of the air, taking eight measures of oxygen

to one of itself, to form nine measures of water, which is deposited on the windows and walls, if provision is not made for its escape; then the carbon unites with a portion of the oxygen to form carbonic acid gas, by weight, of the carbon combining with sixteen parts, by weight, of oxygen. In the ventilation of large rooms, churches, town-halls, &c., it is desirable to have shafts to admit fresh air, and one for the escape of foul air. A plan has been introduced of late years, which consists in admitting a current of fresh air at the upper part on one side, according to the direction of the wind; that on the right of the room entering by the skirting - board, which is pierced with small holes, or narrow slits one-sixteenth of an inch in width, and nearly the depth of the skirting; and that on the left, passing through the floor. The outlet for the vitiated air is placed in the centre of the ceiling over the chandeliers, and this is provided with a valve, which opens upwards; above this is a gaslight, which rarefies the air, and so draws up the foul air from the room, like a cupping-glass does the blood from our bodies. The chief points requiring attention in ventilating rooms or houses consist:-1. Of having an inlet for fresh air, and an outlet for vitiated air; 2. The air admitted should be as pure as possible, free from local vitiations, such as drains, smoke of manufactories, &c.; 3. When air is admitted into an apartment, it should be at the lowest part, and the aggregate area of admission should be twice as great as that of the outlet; 4. When there are galleries in a hall, church, &c., they should be supplied with fresh air from the outside of the building, and not from the body of the room; 5. Air may be warmed when admitted into a large room, by making it pass over pipes filled with hot water; 6. All ventilating shafts, chimneys, &c., should be as smooth inside as possible, as every projection impedes the currents of air. Ventilation is required in all apartments, even our stables and cow-houses, but especially in our sleeping apartments. The want of this essential preservative of health occasions much disquietude to the system generally, as any one may perceive who has for any short period of time stopped in a close apartment.

CONVERSATIONS ON GEOLOGY. (Continued from page 315, Vol. III. New Series.)

STEPHEN. Oh, papa, I met John Jones to-day, and began to tell him about geology; but he asked me what it was, and what was the use of it, and I could not tell him very well.

PAPA. I have already told you what the word means, and if any one asks you again, you can say that geology is the science which endeavours to make out the structure of the earth's crust, and investigate the fossils found in the different strata. That will be a sufficiently accurate definition for your purpose. But I want to tell you a little more about granite, because it appears to have played a very important part in our world's past history. You can easily, by a little practice, distinguish the three minerals in it. The quartz is generally of a greyish-white colour, and is not acted upon by acid, and you cannot scratch it with your knife. The amethyst at the end of my pencil-case is a violet quartz.

WILLIE. Oh, papa, but will you let me try to scrape the end of your pencil-case? PAPA. Oh, yes, if you will only try the

stone.

WILLIE. I can't scrape it, papa.

PAPA. Well, I am glad you have satisfied yourself. The felspar and mica you can easily scratch; and you can distinguish between them by the mica being formed of thin plates, one upon another, so that you can split it up into thin bits. Mica, too, is transparent, which felspar is not. You see what a silvery look it has, and from that circumstance it is often called cat's silver and cat's gold. The English name also has reference to its glittering appearance, being derived from the Latin word micare, to shine or glitter. Now I think you ought to be able to distinguish the minerals composing granite. Now, geologists say that there exists, at the lowest part of the earth's crust of which we know anything, a sort of layer of granite-that granitic rock, in fact, forms a skeleton on which the stratified rocks rest. All these stratified rocks are by some supposed to have been formed from granite. You know that in an old building you generally find that the exposure to the air, and the effects of wind and

cess.

frost, &c., have caused the stones to become decayed; weathered is the term employed by geologists to denote this proEven granite, which is an exceedingly hard rock, has been known to have been weathered to the depth of three inches in six years. When the felspar in the granite is decomposed, it becomes a fine clay. The Chinese call it kaolin, and use it in the manufacture of their finest china; and the same substance is used, too, in England, for I believe that 12,000 tons of this decomposed felspar are annually brought from Cornwall for the use of the potteries. Now, there is a rock called gneiss, which scarcely differs from granite in mineral composition; but the quartz and other materials of which it is composed are evidently waterworn; instead of the angles of the minerals being sharp, they are rounded; in fact, gneiss is granite which has been decomposed-deposited as sediment from water, and then altered by subterranean heat. Now granite is an unstratified rock of igneous (ignis, fire) origin; while gneiss is a stratified rock of aqueous (aqua, water) origin. But the heat to which gneiss has been subjected since it was deposited as sediment has produced a change in it; so that it, and several others which have undergone a similar alteration, are known as altered rocks, or as geologists express it, metamorphic rocks.

WILLIE. Oh, what a hard word.

PAPA. I will always tell you the meaning of the "hard" words, and you must try to remember them. This word metamorphic comes from a Greek word meaning to change, which you must bear in mind. But to proceed. We can easily understand how gneiss was formed from granite. You know I said just now that granite seemed to form the foundation, or skeleton, on which the other rocks rest. Now, taking it for granted that the first solid crust that our globe had was formed of cooled granite, we see that this granite must have been subjected to the decaying influences of the atmosphere, and to the wearing away action of the water. The streams and rivers which then existed would carry down all the particles that became worn off the granite into the sea; there they would sink to the bottom, and the heat of the globe would probably