until a rainstorm stopped it. The English covered up their guns, but the enemy took no such precaution. Mir Mudin, the only loyal general of the nawab's army, thinking that Cl1ve's guns were as useless as his own, made a disastrous cavalry charge upon them, he lost his own life, and his colleagues then had the game in their hands. Mir Tagar persuaded the nawab to ret1re into the entrenchments. St Frais stood fast until one of Clive's officers, Major Kilpatrick, successfully drove him in. Clive followed up this success by cannonading the camp at close range. But the rank and file of the native army, ignorant of the treachery of their leaders, made a furious sortie. For a time Clive was hard pressed, but his cool generalship held its own against the undisciplined valour of the enemy, and, noticing Mir Jagar's division in his rear made no move against him, he led his troops straight against the works. After a short resistance, made chiefly by St Frais, the whole camp fell into his hands. At a cost of 23 killed and 49 wounded this day's work decided the fate of Bengal. The historic grove of mangoes, in which Clive encamped on the previous night, has been entirely washed away by changes in the course of the river, but other relics of the day remain, and a monument has recently been erected.
PLASTER, a mixture of lime, hair and sand, used to cover rough walling of lathwork between timbers (see Plaster-work),
also a line white plaster of gypsum, generally known
as “plaster of Paris” The word (also as “plaister”) is used in
medicine of adhesive mixtures employed externally for the
protection of injured surfaces, for support of weak muscular
or other structures, or as counter-irritants, soothing applications
&c. The ultimate derivation of the word is the Gr. έμπλαοτρον
or έμλαστον in the medical sense, from έν, on, and πλάσσειν to daub or smear.
PLASTER OF PARIS, a variety of calcined gypsum (calcium sulphate) which forms a hard cement when treated with water (see Cement). The substance obtained its name in consequence of being largely manufactured in the neighbourhood of Paris.
PLASTER-WORK, in building. Plastering is one of the
most ancient of handicrafts employed in connexion with building
operations, the earliest evidence showing that the dwellings of
primitive man were erected in a simple fashion with sticks and
plastered with mud. Soon a more lasting and sightly material
was found and employed to take the place of mud or slime, and
that perfection in the compounding of plastering materials was
approached at a very remote period is made evident by the
fact that some of the earliest plastering which has remained
undisturbed excels in its scientific composition that which we
use at the present day The pyramids in Egypt contain plasterwork
executed at least four thousand years ago (probably much
earlier) and yet existing, hard and durable, at the present time.
From recent discoveries it has been ascertained that the principal
tools of the plasterer of that time were practically identical in
design, shape and purpose with those used to-day. For their
finest work the Egyptians used a plaster made from calcined
gypsum just like the “plaster of Paris” of the present time,
and their methods of plastering on reeds resemble in every way
our “lath, plaster, float and set” work. Hair was introduced
to strengthen the “stuff ” and the whole finished somewhat
under an inch thick. Very early in the history of Greek architecture
we find the use of plaster of a fine white lime stucco.
Such has been found at Mycenae The art had reached perfection
in Greece more than five centuries before Christ, and plaster
was frequently used to cover temples externally and internally,
in some cases even where the building was of marble. It formed
a splendid ground for decorative painting, which at this period
of Grecian history had reached a very high degree of beauty.
The temple of Apollo at Bassae, built of yellow sandstone about
470 B C, is an excellent example. Pavements of thick, hard
plaster, stained with various pigments, were commonly laid in
Greek temples The Roman architect Vitruvius, in his book on
architecture written about 16 B C, gives detailed information
concerning the methods of making plaster and the manner of
using it. “The lime used for stucco,” he writes, “should be
of the best quality and tempered a long time before it is
wanted for use. The Greeks, besides making their stucco
work hard with thin coats of marble-dust plaster polished with
chalk or marble, caused the plaster when being mixed to be
beaten with wooden staves by a great number of men. Some
persons cutting slabs of such plaster from ancient walls use
them for tables and mirrors.” Pliny the elder tells us that
“no builder should employ lime which had not been slaked at
least three years,” and that “the Greeks used to grind their
lime very fine and beat it with pestles of wood.” In England
the walls of large houses and mansions were formerly plastered
above the wainscoting and coloured, while the ornamented
plaster ceilings of the time of Henry VIII, Elizabeth and
James I, are st1ll the admiration of lovers of the art. Still earlier
specimens of the plasterer's skill are extant in the pargeted and
ornamented fronts of half-timbered houses With regard to the
smaller buildings, comprising small dwelling-houses and cottages,
the general application of plaster is of comparatively late
date, for wainscoted walls and boarded ceilings or naked joists
alone are frequently found in houses of not more than a century
old both in England and on the Continent.
In the more common operations of plastering, comparatively few tools and few materials are required, but the workman efficient in all branches of the craft will possess a very large variety of implements The materials of the workman are laths, lath nails, lime, sand, hair, plaster of paris, and a variety of cements, together with various ingredients to form colouring washes, &c
Wood laths are narrow strips of some straight-grained wood, generally Baltic or Amerlcan fir, in lengths of from two to four or five feet to sult the distances at which the timbers of a floor or partition are set.Lathing. Laths are about an inch wide, and are made in three thicknesses; “ single ” (18 to 316 in. thick), “lath and a half" (14 in. thick), and “double” (38 to 12 in. thick). The thicker laths should be used in ceilings, to stand the extra strain, and the thinner variety in vertical work such as partitions, except where the latter will be subjected to rough usage, in which case thicker laths become necessary. Laths are usually nailed with a space of about 38 in. between them to form a key for the plaster. Laths were formerly all made by hand. A large quantity, however, are now made by machinery and are known as sawn laths, those made by hand being called rent or riven laths. Rent laths give the best results, as they split in a line with the grain of the wood, and are stronger and not so liable to twist as machine-made laths, some of the fibres of which are usually cut in the process of sawing. Laths must be nailed so as to break joint in bays three or four feet wide with ends butted one against the other. By breaking the joints of the lathing in this way the tendency for the plaster to crack along the line of joints is diminished and a better key is obtained, Every lath should be nailed at each end and wherever it crosses a joist or stud. All timbers over three inches wide should be counter-lathed, that is, have a fillet or double lath nailed along the centre upon which the laths are then nailed. This is done to preserve a good key for the plaster. Walls liable to damp are sometimes battened and lathed in order to form an air cavity between the damp wall and the plastering
Lathing of metal, either of wire of in the form of perforated sheets, is now extensively used on account of its fire-proof and lasting quality.Metal Lathing. There are very many kinds of this material made in different designs under various patents, the best-known in England being the Jhilmill, the Bostwick, and the Expanded Metal lathing. The two last-named are also widely used in America.
Lathing nails are usually of iron, cut, wrought or cast—and in the better class of work they are galvanized to prevent rusting. Zinc nails are sometimes used, but are costly.
The lime principally used for internal plastering is that calcined from chalk or other nearly pure limestone, and is known as fat, pure, chalk or rich lime.Limes. Hydraulic limes, which are referred to in the articles Brickwork and Mortar, are also used by the plasterer, chiefly for external work. Perfect slaking of the calcined lime before being used is very important as, if used in a partially slaked condition, it will “blow” when in position and blister the work. Lime should therefore be run as soon as the building is begun, and at least three weeks should elapse between the operation of running the lime and its use.
Hair is used in plaster as a binding medium, and gives tenacity to the material.Hair. Ox-hair, which is sold in three qualities, is the kind usually specified, but horsehair, which is shorter, is sometimes substituted in its stead or mixed with the ox-hair in the lower qualities. Good hair should be long, strong, and free from grease and dirt, and before use must be well beaten to separate the lumps. In America, goats' hair is frequently used,
