The proportion of mortar, or cement, when made up, to the lime, or cement and sand before made up, is as 2 to 3.

Lime, or cement and sand, to make mortar, require as much water as is equal to one third of their bulk, or about 51⁄2 barrels for a rod of brickwork built with mortar.

1 cubic yard of chalk lime, 2 yards of road drift or sand, and 3 bushels of hair, will cover 75 yards of render and set on brick, and 70 yards on lath, or 65 yards plaster and render 2 coats and set on brick, and 60 yards on lath; floated work will require about the same as 2 coats and set.

I bundle of laths and 500 nails will cover about 4 yards.

Mortar

1 hundred of lime contains 25 striked bushels, or 100 pecks. It is a measure 3 feet square, and 3 feet 1 inch deep 1 ehaldron of lime is equivalent to 57765 cubic feet, or rather more than 2 hundred.

18 heaped bushels, 22 striked bushels, or yard cube, a single load of sand, mortar, &c

1 double load is equal to 36 heaped bushels,

1 hod of mortar is equal to 1134 cubic inches, or 8 duodecimal inches, or 9 x 9, and 14 inches long.

2 hods of mortar make a bushel nearly.

Cement.

1 barrel of cement is 5 bushels, and weighs 3 cwt. I rod of brickwork, in cement, requires 36 bushels of cement and 36 bushels of sand.

1 yard, or 9 feet superficial of 14 inches, or 14 brickwork, in cement, requires about 24 bushels,

1 yard superficial of pointing to brickwork, in cement, requires about one eighth of a bushel.

1 yard square of plastering, in cement, requires three fourths of a

bushel.

In

Carpentry and Plastering are measured by the square foot or yard; or, in moulded and ornamental work, by the linear foot. extensive work the square of 100 feet is also used. Paving is measured by the square yard.

Digging, &c.

234 cubic feet of sand, 17 ditto clay, 18 ditto earth, 13 ditto chalk, equal to a ton.

A cubic yard of earth, before digging, will occupy about 11 cubic yard when dug.

27 cubic feet, or 1 cubic yard, contains 21 striked bushels, which, is considered a single load, and double these quantities a double load.

18 cubic feet of night soil, 1 ton.

2 tons of ditto is the quantity a cart contains; 6 feet long, 3 feet 3 inches wide, by 2 feet 4 inches deep, or 45 feet cube.

Coarse Stuff.

Coarse stuff, or lime and hair, as it is sometimes called, is prepared in the same way as common mortar, with the addition of hair procured from the tanner, which must be well mixed with the mortar by means of a three-pronged rake, until the hair is equally distributed throughout the composition. The mortar should be first formed, and when the lime and sand have been thoroughly mixed, the hair should be added by degrees, and the whole so thoroughly united that the hair shall appear to be equally distributed throughout.

Fine Stuff.

This is made by slaking lime with a small portion of water, after which so much water is added as to give it the consistence of cream. It is then allowed to settle for some time, and the superfluous water is poured off, and the sediment is suffered to remain till evaporation reduces it to a proper thickness for use. For some kinds of work it is necessary to add a small portion of hair.

Stucco for Inside of Walls.

This stucco consists of fine stuff already described, and a portion of fine washed sand, in the proportion of one of sand to three of fine stuff. Those parts of interior walls are finished with this stucco which are intended to be painted. In using this material, great care must be taken that the surface be perfectly level, and to secure this it must be well worked with a floating tool or wooden trowel. This is done by sprinkling a little water occasionally on the stucco, and rubbing it in a circular direction with the float, till the surface has attained a high gloss. The durability of the work very much depends upon the care with which this process is done, for if it be not thoroughly worked it is apt to crack.

Gauge Stuff.

This is chiefly used for mouldings and cornices which are run or formed with a wooden mould. It consists of about one fifth of plaster of Paris, mixed gradually with four fifths of fine stuff. When the work is required to set very expeditiously, the proportion of plaster of Paris is increased. It is often necessary that the plaster to be used should have the property of setting immediately it is laid on, and in all such cases gauge stuff is used, and consequently it is extensively employed for cementing ornaments to walls or ceilings, as well as for casting the ornaments themselves.

Higgins' Stucco.

To fifteen pounds of the best stone lime add fourteen pounds of bone ashes, finely powdered, and about ninety-five pounds of clean, washed sand, quite dry, either coarse or fine, according to the nature of the work in hand. These ingredients must be intimately mixed, and kept from the air till wanted. When required for use, it must be mixed up into a proper consistence for working with lime water, and used as speedily as possible.

Parker's Cement.

This cement, which is perhaps the best of all others for stucco, as it is not subject to crack or flake off, is now very commonly used, and is formed by burning argillaceous clay in the same manner that lime is made; it is then reduced to powder, by the process described in a previous part of this work. The cement, as used by the plasterer, is sometimes employed alone, and sometimes it is mixed with sharp sand; and it has then the appearance, and almost the strength, of stone. As it is impervious to water, it is very proper for lining tanks and cisterns.

Hamelein's Cement.

This cement consists of earthy and other substances insoluble in water, or nearly so; and these may be either those which are in their natural state, or have been manufactured, such as earthenware and china; those being always preferred which are least soluble in water, and have the least color. When these are pulverized, some oxide of lead is added, such as litharge, gray oxide, or minium, reduced to a fine powder; and to the compound is added a quantity of pulverized glass or flint stones, the whole being thoroughly mixed and made into a proper consistence with some vegetable oil, as that of linseed. This makes a durable stucco or plaster, that is impervious to wet, and has the appearance of stone. The proportion of the several ingredients is as follows:-to every five hundred and sixty pounds of earth, or earths, such as pit sand, river sand, rock sand, pulverized earthenware or porcelain, add forty pounds of litharge, two pounds of pulverized glass or flint, one pound of minium, and two pounds of gray oxide of lead.

Mix

the whole together, and sift it through sieves of different degrees of fineness, according to the purposes to which the cement is to be applied.

The following is the method of using it:-To every thirty pounds' weight of the cement in powder add about one quart of oil, either linseed, walnut, or some other vegetable oil, and mix it in the same manner as any other mortar, pressing it gently together, either by treading on it, or with the trowel; it has then the appearance of moistened sand Care must also be taken that no more is mixed at one time than is required for use, as it soon hardens into a solid mass Before the cement is applied, the face of the wall to be plastered should be brushed over with oil, particularly if it be applied to brick, or any other substance that quickly imbibes the oil; if to wood, lead, or any substance of a similar nature, less oil may be used.

Maltha, or Greek Mastic.

This is made by mixing lime and sand in the manner of mortar, and making it into a proper consistency with milk or size, instead of water.

Plaster in imitation of Marble.

This species of work is exquisitely beautiful when done with taste and judgment, and is so like marble to the touch, as well as appearance, that it is scarcely possible to distinguish the one from the other. We shall endeavor to explain its composition, and the manner in which it is applied; but so much depends upon the workman's execution, that it is impossible for any one to succeed in an attempt to work with it without some practical experience.

Procure some of the purest gypsum, and calcine it until the large masses have lost the brilliant sparkling appearance by which they are characterized, and the whole mass appears uniformly opaque. This calcined gypsum is reduced to powder, and passed through a very fine sieve, and mixed up, as it is wanted for use, with Flanders glue, isinglass, or some other material of the same kind. This solution is colored with the tint required for the scagliola, but when a marble of various colors is to be imitated, the several colored compositions required by the artist must be placed in separate vessels, and they are then mingled together in nearly the same manner that the painter mixes his color on the pallet. Having the wall or column prepared with rough plaster, it is covered with the composition, and the colors intended to imitate the marble, of whatever kind it may be, are applied when the floating is going on.

It now only remains to polish the work, which, as soon as the composition is hard enough, is done by rubbing it with pumicestone, the work being kept wet with water applied by a sponge. It is then polished with Tripoli and charcoal, with a piece of fine linen, and finished with a piece of felt, dipped in a mixture of oil and Tripoli, and afterwards with pure oil.

Composition.

This is frequently used, instead of plaster of Paris, for the ornamental parts of buildings, as it is more durable, and becomes in time as hard as stone itself. It is of great use in the execution of the decorative parts of architecture, and also in the finishings of picture frames, being a cheaper method than carving, by nearly eighty per cent.

It is made as follows: Two pounds of the be whitening, one pound of glue, and half a pound of linseed oil are heated together, the composition being continually stirred until the different sub stances are thoroughly incorporated. Let the compound cool, and then lay it on a stone covered with powdered whitening, and heat it well until it becomes of a tough and firm consistence. It may then be put by for use, covered with wet cloths to keep it fresh. When wanted for use it must be cut into pieces, adapted to the size of the mould, into which it is forced by a screw press. The ornament, or cornice, is fixed to the frame or wall with glue, or with white lead.

To make Glass Paper.

Take any quantity of broken glass (that with a greenish hue is the best), and pound it in an iron mortar. Then take several sheets of paper, and cover them evenly with a thin coat of glue, and, holding them to the fire, or placing them upon a hot piece of wood or plate of iron, sift the pounded glass over them. Let the several sheets remain till the glue is set, and shake off the superfluous powder, which will do again. Then hang up the papers to dry and harden. Paper made in this manner is much superior to that generally purchased at the shops, which chiefly consists of fine sand. To obtain different degrees of fineness, sieves of different degrees of fineness must be used

To make Stone Paper.

As in eleaning wood-work, particularly deal and other soft woods, one process is sometimes found to answer better than another, we may describe the manner of manufacturing a stone paper, which, in some cases, will be preferred to sand paper, as it produces a good face, and is less liable to scratch the work. Having prepared the paper as already described, take any quantity of powdered pumice-stone, and sift it over the paper through a sieve of moderate fineness. When the surface has hardened, repeat the process till a tolerably thick coat has been formed upon the paper, which, when dry, will be fit for use.