"The mass is now subdivided into solids of a regular form, by means of a mould. This operation is executed with rapidity. A moulder, working by the piece, makes on an average five thousand prisms a day, which will measure about six cubic metres (211.S cubic feet English). These prisms are arranged on drying shelves, where in a short time they acquire the degree of desiccation and hardness proper tbr calcination." These artificial limes are intended to supply the place of the natural ones in those countries where a•7illaceous lime stone cannot be obtained. The price at which they were sold in Paris a few years back, was about 1'2 5s. per cubic yard English.
Mil/ha. and mastic, are cements, whose hardness depends on the oily or mucilaginous substances that enter into their composition. The use of these is at present very limited in Europe ; but they were highly esteemed by the ancients, especially for stucco. The nialllta of the Greeks seems to have been mote simple than that employed by the Roman architects: at least we are informed. that Pan:villas, the brother of Phidias, lined the inside of the temple of Minerva, at Elis, with stucco, in which the usual ingredients of sand and lime were mixed up with milk, instead of water, some saffron beitng added to give it a yellow tinge. The Roman Inaltha, according to Pliny, was prepared as follows : Take fresh-burnt lime, and slack it with wine, then beat it up very well in a mortar, with hogs' lard and figs: this cement. if well made, is excessively tenacious, and in a short time becomes harder than stone ; the surface to which it is to be applied is to be previously oiled, in order to make it adhere. Another kind almost equally strong, and considerably cheaper, was prepared by beating up together fine slacked lime, pul verized iron scales, and bullocks' blood.
In the preparation of maltha, as well as of every other kind of mortar, so much depends on the manipulation, and on the care and long beating of the ingredients, that those countries in which labour is of the least value, possess, in general. the best mortar. Hence, no doubt, principally arises the unrivaled excellence of the mortar made by the Tunisians, and other inhabitants of the northern coast of Africa. Dr. Shaw gives the following account of their manner of preparing their mortar : One measure of sand, two of wood-ashes, and three of lime, being previously sifted, are mixed together, and sprinkled with a little water: after the mass has been beaten some time, a little oil is added : the beating ,is carried on for three or four days successively, and, as the evaporation in that hot climate is Considerable, the cement is kepi in a proper degree of softness by the alternate addition of small quantities of water and oil. The cement, being eompleted, is in
the usual manner, and speedily aequires a stony hardness.
The term mai Ma is also applied to a variety of bitumen or mineral pitch of a viscid and tenacious character ; unctuous to the bawl', and exhaling a bituminous odour. This sub stance. as also Asphalte, (see ASPIIALTE,) has been success fully used as a cement.
The celebrated ch imam, of India, is a species of ;flotilla which has been used in that country from time immemorial. The method in which it is prepared at Madras is as follows:— Take fifteen bushels of pit-sand, and fifteen bushels of stone-lime ; slack the latter with water, and when it has Ulm to powder, mix the two ingredients together, and let them remain for three days untouched. Dissolve ;20 lbs. of molasses in water, and boil it peek of gramm, (a kind of pea,) and a peek of mirabolans to a jelly ; mix the three liquors, and incorporate part of the mixture very accurately with the lime and sand. so as to make a very fluid cement ; some short tow is then to be beaten well into it, and it will be fit for use. The bricks are to be bedded in as thin a layer as possible of this mortar ; and when the workmen leave off, though but for an hour, the part where they recommence working is to he well moistened with some of the above lignor before the appli ' cation of fresh mortar. When this composition is used for stucco. the whites of four eggs, and four ounces of butter milk. are to he mixed up with every half bushel of cement, and the composition is to be immediately applied.
Mastic is an external composition possessing peculiar pro perties, which, in some eases. render it superior to Roman cement, having the power of resisting heat and adhering to iron, copper. and even glass, with equal tenacity. It is generally applied to the exteriors of mansions, but it may also be very beneficially used for laying the floors of halls, kitchens, &c.