14 FEBRUARY 1920, Page 6

PIS1 DE TERRE IN THE PAST.

" PISE (a. F. piste, subst. use of pa. pple. of piser, to beat, pound (earth) : L. pisare, pinedre, to beat, pound, stamp.

Stiff clay or earth kneaded, or mixed with gravel, used, esp. in France and some parts of England, for building cottages, walls, etc., by being rammed between boards which are removed as it hardens ; also a name for this mode of building.

1797. H. Holland in Coin. Board Agric.,' I. 387. The ward pise is a technical term and it has been retained in this transla- tion because it cannot be rendered by any adequate word in the English language.'

1305. R. W. Dickson, Pract. Agric.' (1807), I. 136 : Building in what is termed pied or simply by compressing well-wrought earth in moulds.'

1852. Wiggin's Embanking,' 82 : ' A wall of pied or rammed gravel in a frame might very judiciously be adopted for two or three feet of the centre of the bank.'

1890. B. Boldrewood," Squatter's Dream,' vii. The new cottage which he had judiciously caused to be built of pied or rammed earth.'

b. attrib. or adj. as pied building, wall, work.

1840. Cottager's Man.' 30 in. Libr. Thief. Knowl. Husb. "Walls formed of earth in the pied manner.'

1849. Ecclesiologiet,' IX., 217 We a. . think that what our correspondent calls Pia building is common in Devonshire . . . and known by the name of cob-building.'

1875. Knight Diet. Mech.,' 1714/1: ' The beet material for pice-work is clay with small gravel-stones interposed through. it.' " —(The Oxford Dictionary.)

IN the history of building in Pis‘ de Teire, the testimony .1 of Isidorus, Archbishop of Seville, who died in 636 A.D., is of great interest. In the ninth chapter of the XVth Book of his Etrrugogiarurn he emphatically appraises the work of Pise, and establishes its antiquity, saymg :— " Formatum, sive formatium, in Africa, vel Hispania parietes de terra appellant, quoniam in forma eircumdates duabus utrinque tub ulis inferciuntur, verius quam struuntur. Aevis durant incorrupti, ventis, ignibus, omni caementi fortiores."

(Earth ern walls are called formatum or formatium in Africa and Spa in, since being surrounded by a frame they are stuffed between two boards, rather than built up. They last un- damaged by wind or fire for ages, being stronger than any cement.)

The work quoted from is encyclopaedic in its scope, and contains, among other things. , a variety of information concerning natural phenomena, as well as an assortment of facts about buildings and the materials for their con- struction. The learned author must have had ample opportunity for observing what he describes in the above quotation. His editor, in Migne's Patrologia, 1862, has the following note :— " Formatum, sive formatium a lib. XXX Cap 14 Plini qui emendandus est ex hoc loco Isidori. Retinemus nos hodie idem nomen, nam formatium Hispani Hormigon dicimus."

(Formatum or formatium, Pliny, Book XXX., oh. xi v., who should be corrected by this passage of Isidorus. We keep the same name to-day, for in Spain we call formatium—Hornugon.) " Emendandus " presumably refers to the spelling " formacean " adopted by Pliny.

Palladius (Book I. ch. xxxiv.) states without comment that garden walls were in his day made either of Pise, mud with small stones intermixed, or of stone. The date of his writing, though uncertain, is conjectured to be the fourth century A.D. He says :- " Munitions multa sent genera : alii lute inter formes clause parietes figuratos ex partibus imitantur : quibus subpetit, macerias luto et lapide excitant : pler:que sine luto congests in ordinem saxa componunt."

This, though the construction is obscure, and the text not improbably corrupt, may perhaps be translated as follows :- "Walls are of many kinds: some imitate walls made of dis- crete parts by placing earth between frames : those for whom it suffices erect walls of mud and small stones ; while very many build them of larger stones arranged in regular order without mud."

Lutunt, strictly mud, is probably used in a loose sense for earth, either dry or wet. It will be noted that Paladins appears to allude slightingly to walls made with stones and mud, compared with those of either rise, or stone only.

According to Cointereaux, who wrote at the end of the eighteenth century, Pise de Terre had been practised for ages in the neighbourhood of Lyons. Woods, an English writer who visited this locality in 1806, is quoted in the Architectural Publication Society's Dictionary. He de- scribes the Pise walls as made of gravel and clay, formed into blocks in a sort of mould on the work itself, and separated by pretty thick beds of mortar. On p. 723 of the fifth volume of the Encyclopedie Pratique de l'Agrieul- ture published in 1865, however, not only is Pise stated to be still used in England, but it is praised for its cheapness and superiority over other methods of construction. Referring to parts of France where stone is not available, the writer says :— " L'absenee de pierces oblige a faire les constructions rurales en tem. Male au lieu de lea employer par la mode perfectionnhe du pied, que is nature des torres admettrait presque partout, on la combine avec le boil sous forme de bauge ou torchis, ce qui donne des bittiments qui, apres quelques • annees d'existence, laissent passer non seulement le vent, et la pluie, male lee rats, fouinee, belettes, renarda et jusqu'au loupe."

(The absence of stone makes it necessary to construct rural edifices of earth. But instead of making use of it according to the perfected method of Pisd, which the nature of the soils would almost everywhere permit, it is combined with wood in the form of cob, which gives buildings that, after standing for some years, allow the passage not only of wind and rain, but of rats, martens, weasels, foxes, and even wolves.)

This is delicious. When is a house emphatically not a, home ? When it fails to keep the wolf—I, was going to say from the door—but no, when it lets him come lolloping, through the walls. Not Ilse walls, though. No historical account of Pig de Terre would be complete without mentioning the important innovation of moulding the compressed earth into blocks, resembling hewn stone. Originally invented by Cointereaur more than a hundred years ago, they were independently rediscovered, and have been used for pillars and partition walls by Mr. St. Lost Strachey. Loudon thus describes Cointereaux's process (Encyclopaedia of Agriculture, § 3074) " Earth prepared in the same manner as for rammed walls is put into a mould, or box, of any size, generally that of the proposed wall's thickness in width, one or two feet long, and about one foot high. The mould is a strong oaken or iron box, and the earth being placed in it is compressed either by the action of a press, acted on by a lever or a screw, or a stamping engine similar to the great forge hammer. The atone, or solid body of earth thus acquired, is then used in the same manner as hewn stone." (Italics inserted.) Might not the employment of such blocks as these prove economical where a number of Pia structures require to be erected simultaneously, the expense involved in constructing a number of large frames being obviated ? One stamping engine, hired for a limited time, could make the whole of the blocks needed, which might be stored for use. It is to be noted that better blocks should be formed by percussion, than if the earth were subjected to merely static pressure by lever or screw. It is not too much to hope that the experiments now being conducted may lead to an authoritative verdict on this point. The fact that Pig de Terre structures, such as Hannibal's towers, have outlasted the races which built them is well attested. Aevis durant incorrupti. But travellers in these regions might add much to our information in the light of recent knowledge. Especially might they elucidate the vexed questions whether any of the watch-towers built by the Carthaginians were constructed of cob, and, if so, in what relative state of repair they are compared with the Pise towers. However surprising it may be, even mud structures appear to exhibit remarkable permanence under most unfavourable climatic conditions, an argument a fortiori for the durability of Pith.

Chambers's Journal some fifty years ago quotes Rich as describing " the sunburnt bricks of Birs Nimroud and the Majallibe as ' looking like thick clumsy sods of earth, in which are seen broken reeds, or chopped straw, used for the obvious purpose of binding them.' " Even though the individual bricks must, we may suppose, have been protected by the similar debris under which they lay, it is surely not a little remarkable that they should be individually recognizable after fully three thousand years of exposure to the torrential rains of the Euphrates Valley. Nor is it without interest that the first industrial trouble recorded in history relates to the use of straw in cob bricks. We were taught, when we read that Pharaoh com- manded " There shall no straw be given you, yet shall ye deliver the tale of bricks," to call him a heartless tyrant ; stifling our obstinate questioning as to what straw had to do with bricks. What indeed has it to do with good bricks ? In the light of present knowledge should we not perhaps regard Pharaoh as an economist, if not an actual reformer ?

The Spectator has been advocating, not bricks merely, but entire walls made without straw. Was Pharaoh the first of Pig experts, fighting a vile conspiracy of blatant cobbism ? At least he may have had his just doubts about the use made of straw by the Israelites, for Sir William Willeocks has described how, rummaging near the scene of their labours, he found bricks made entirely of straw veneered with mud, lying by the side of numerous pure mud bricks. If I remember aright, he suggests that the Egyptian overseers were to be deceived by this means, an excuse being afforded for downing tools. Truly the uses of scarcity are manifold ; and labour problems have ever been thorny since Adam, albeit clad in skins, yet 'without shoon, set forth from Accadian Eden to earn his bread by the sweat of his brow, treading warily over the mid-alluvial flats, then as now, we may suppose, strewn profusely with the off-castings of acacia, spiniest of waste- loving shrubs.

As a Postscript I may add an extract from a work, An Encyclopaedia of Civil Engineering, by Edward Cresy (London: Longman, Brown, Green, and Longmans, 1847), sent by a correspondent of the Spectator :— CHAPTER vi.—" Or Pies."

" This method of construction is far more simple than that where unburnt bricks are employed, and by no means so costly ; it is universally adopted in the departments of the Ain, Rhone, and Isere, in France, and forms fire-proof houses, far preferable for cottages to timber framing, and Well suited for barns, stables, or sheds attached to a farm. Walls properly carried up in this material form one entire mass, and covered with a fine coat of plaster will endure for ages, and present an agreeable appearanoe. Rondelet informs us that he repaired, in 1764, an ancient chateau in the department of Ain, which had endured for upwards of 500 years, and that the walls had attained a hardness and com- pactness equal to ordinary stone ; when desired to increase the size of the windows and other apertures, the workmen were obliged absolutely to use the same tools as in a quarry.

Manner of making Piee.—The ante probably suggested the process of preparing earth for building purposes, and in the tropical climates we discover these industrious insects almost rivalling man in the arrangement and strength of their habita- tions : the elevation of their houses exceeds in height five hundred times that of the builders. The termites, which are scarcely a quarter of an inch in size, pile up dwellings 7 feet high, and sometimes as much as 20. Bishop Heber describes some in India which were as much as 7 or 8 feet in circumference ; within were numerous galleries and cells, the principal of which was occupied by the king and queen, placed nearly in the centre ; its floor was more than one inoh in thickness, formed of clay, and the roof one solid well-turned, oval arch of considerable thickness.

The Termes mordax and Atrox, or turret-building ants, form their habitations with a well-tempered black earth, often three feet in height, in form of a conical mushroom ; all the varieties of ants select a fine clay for their cells, galleries and bridges ; lining their rooms with a composition formed of wood and gum, which these insects seem to have the instinct to prepare in a very fine state, and to lay on like a coat of cement : thus it is that man may receive instruction from a close observation of the habits of the animal creation. All earth is suited for pied work, but the best is clay which contains small gravel, and of such a consistence that it can be dug with the common spade every kind of earth that will sustain itself, with a small slope, is adapted for the purpose and may be successfully used. To prepare it, after beating thoroughly, it must be passed through a screen to take away the atones beyond the size of a common hazel nut ; and if not moist it must be watered, and turned over with a shovel until it has acquired a regular consistence, which is known by moulding it by the hand, or between the fingers, and then throwing it into a vessel, when, if it retains the shape given to it, it may be considered as fit foruse. . . .

Experience has shown that in an ordinary climate walls of

18 or 20 inches in thickness finished about the commencement of May, are sufficiently dry in September or October for plaster- ing ; those finished in July or August may generally be com- pleted before the frost and rain have any effect upon the work ; although pied is formed of earth scarcely wetted, whilst the unburnt bricks of the ancients were kneaded with straw and water it is nevertheless prudent to regard Vitruvius's observa- tion, f not to apply plaster unless the middle is dry.' The pied which is made during the hot months soon dries in the exterior ; but the moisture is confined to the centre, from whence it escapes slowly, rising by degrees to the surface ; if covered with plaster, it insinuates itself between this and the pied, occasioning the outer coat to fall off. There is no fear of the action of the air when it is well done, for the drier it is the better the plaster adheres ; in the department of Isere there are ancient houses of pied that have never been plastered on the exterior, and which still resist all the inclemencies of the weather : when the earth is poor, or not consistent enough, by being wetted with lime- water, or grouting formed of mortar, it hardens, the surface becomes improved, and a building might be carried up with its walls so even as not to require any coat of plaster." P. D. T.