Chapter IV: Part 4

"I am very interested to hear that you are proposing to use an hydraulic rammer for making blocks. I have thought a good deal about this pressure business. I am trying to scrutinise the thing from 'the inside,' so to speak. I am trying to trace out how Nature makes rock. That helps us to understand pise. Nature made all the stratified rocks out of what was once fine loose earth and mud. Rivers carried the mud out to sea. Waves pounded and gnawed the shores and got down some more stuff. The tides went forth and back and shovelled and levelled at the sea-bottom. Some more mud on top of that, and a few hundred or thousand feet of the heavy water on top of that--and Nature's pise was in its making. But why do these mud particles stick together for ever even after that stratum is raised up high above the sea and the pressure is discontinued? That is the counterpoint of the whole problem. What is gravitation? Is it some form of magnetic or electric energy? We don't know. Do particles of mud grip and hold each other if they are forced together close enough to be united by some sort of magnetic or electric energy? Or do the particles only get a 'mechanical' grip on each other? However that may be, we seem to know now that we can make them grip by bringing them closely together. It would seem important, then, that we must bring as much of particle surfaces together within any given cubic space as we possibly can; that is, we must have as little of 'holes,' 'empty spaces,' pores and channels as possible in the mass, in the pressed wall. This, then, would in turn make it important that plenty of very fine (small) particles must be present in the mass--and so well distributed among the coarser particles as to be on hand close by wherever there can be one more chance for a small particle to fill a little chamber that the coarser particles would like to bridge over. We can think of how well Nature was fitted for this work of shuffling over all the particles at the sea-bottom and under great water pressure till she got every particle into the niche where it would exactly fit. She used waves, tides, and gulf streams as shovels and mixers and packers, and the water above as 'hydraulic rammer.' Looking at the pise matter in this way, it would appear that both the _mixing_ and the _shuffling_ are of vital importance. And by 'shuffling' I mean in this connection only that the smaller and larger particles get a chance to shift over a little during the process of pressing the earth together to hardness, so that the pressure may not work only and exclusively in a straight downward direction, but in a sort of wavy zigzag direction as well--much as when a street-roller is working the macadam and gravel a little forth and back at the same time as downward. I have a great respect for old tools which are the outcome of long-time experience and handed-down wisdom. I suspect the presence of some of that sort of experience in the rammer described in your book, p. 59. That tool would do the necessary shifting while attending to its _main_ intention: hammering the mass solidly together downwards. Now for your hydraulic rammer--is it advisable to make it blow or press only in a straight line downward? Maybe there ought to be two or three kinds of strokes alternating--one stroke with a rifled or wavy surface under the rammer--and the next stroke with a _plane_ surface. . . . What sort of witchcraft enters into the effect of _high frequency blows_ as compared with blows with a little longer intervals between? Do the strokes create also some 'magnetic' effect in the pounded earth-mass which helps to fasten the particles to each other? And does this magnetic charge or friction heat, or whatever it is, act more promptly if one keeps on 'striking the iron while hot,' instead of letting the charge 'evaporate' and sneak away between strokes? Two or three of my hairs are turning grey over these questions alone. You compliment me by insinuating that I might stumble across some fruitful idea for the forms or boxes if I speculate a little more on the key-problem. Well, the thing won't leave me alone, so I have thought out several foolish variations and rejected them too. But the last one seems to have a little more vitality, so if it will live till I write my next letter I will tell you about it. One is so apt to follow the temptation of 'perfecting' an apparatus--at the cost of getting away from keeping it cheap, simple--and 'fool-proof.' By this time the idea has grown ripe in my mind, so that I ought to write out a little book on the pise problem in Swedish and have it printed before springtime. Something ought to be done. . . . I have to ask you kindly to permit me to make use of the data contained in your book. To this I will have to add what special precautions we must observe as to foundations in a climate like ours. I intend to treat only the pise method. Cob and chalk methods are not applicable here, as we have such materials only in a few unimportant spots."

Mr. Ellington has long been an admirer and a firm friend of England, and he is good enough to regard his country as indebted to ours for the introduction of pise-building:

"Let me tell you that the help you are giving me now--not me, but my nation--will work as an additional bond that draws us more closely towards each other. . . . Some of our people here have always looked too much towards the South and too little towards the West."

[Headnote: A Pise-Builder's School]

PISE, PRACTICE AND PLANT

Now that so many able architects and enterprising bodies are seriously taking up pise-building, the improvement in plant and technique should be both rapid and considerable. The School of Pise Building established at Hornchurch in Essex, by the Imperial Ex-service Association, should alone provide us with much new and valuable knowledge of a highly practical kind.

It is there, for instance, that various types of shuttering and rammers are being experimentally tested side by side, and their relative efficiency under varying conditions ascertained. Under some conditions it is probable that the floor and roof timbers (destined for use in the house under construction) will be found the most economical and satisfactory form of temporary "shuttering" for the making of the earth walls.

The pise "Test-House," built by Messrs. Alban Richards at their Ashstead works, was built in this way, and proved highly satisfactory.

Another effective and more generally applicable form of shuttering (designed and manufactured by the same firm) is illustrated in the diagram reproduced below. It should be observed that wedges intervene between the movable shutters and the uprights.

The method of employment of the "Mark V" shuttering is well illustrated by the bird's-eye view showing the Newlands cottage under construction.

[Headnote: Alternative Shutterings]

In this matter of shuttering there is still, however, great scope for improvement, and it may be hoped that soon ingenuity and experience will jointly produce a complete pise plant perfectly fulfilling all the many conditions enumerated earlier in the book.

Shuttering made by riveting plain galvanised sheet iron to one side of a corrugated sheet has the qualities of lightness, smoothness, cheapness, and rigidity, and the claims of the inventor and patentee are now being put to the test in actual building.

There now seems little doubt but that pise blocks will be largely used for partitions and chimney stacks where the soil is good enough, and experiments are being made with a view to discovering the best and cheapest way of making earth slabs similar to those of coke-breeze and concrete.

The size aimed at is 18 in. by 18 in. by 3 in., the edges to be tongued and grooved.

Certain "concrete" machines seem to lend themselves to adaptation for the making of earth blocks, but it is necessary to remember that sharp blows are required rather than a steady pressure, and also that we are working with a _dry_ material. The ordinary primitive way of making pise blocks is indicated below.

The hand-rammers are undoubtedly worth study and careful design. A set of three seems to meet all ordinary requirements, and those shown on p. 101 may be taken as typical. They should be of hard-wood, smoothly finished, and provided with long handles. They should be 9 in. to 12 in. long, and about 5 in. by 4 in. at maximum cross section.

In the sketch they are shown "narrow-ways-on." No. 1 is used for preliminary pounding and final finishing, No. 2 for general consolidating, and No. 3 for working along the edges, against window stops, and under cross-ties.

A South African correspondent, Major Baylay, makes interesting comment as regards rammers and local pise practice:

[Headnote: South Africa]

"My experience of all black labour is, that they won't put any 'guts' into it. They therefore want fairly heavy rammers, which they can lift and drop, say a foot, and which will do the rest for them. The heat of the sun and extreme dryness of atmosphere out here make it advisable to cover up completed courses at once with sacking, moist for choice, otherwise it is liable to dry out too quickly and crack. It dries out uncovered at night very well, when there is no rain.

"The red loams of South Africa, where not too sandy, make excellent pise. They or their equivalent are found almost everywhere. In the dry state they set so hard that moisture added just before ramming is useless. A large heap must be made, well damped and covered over with moist sacking, and left until the moisture is distributed throughout the mass. When about four or five days old, in ordinary weather, the earth is ready to use--viz., just wet enough to bind when gripped in the hand. It should be passed through a sieve. I use a sort of 'chicken run,' 8 ft. long, and throw the earth on to it before using. Six feet of it is 1/2-in. mesh, and 2 ft. 1/4-in. mesh; the reason for this is that, if the earth is a little too dry, it does not always bind well with the previous layer. Therefore, put a few petrol tins of the fine earth into the shuttering first in order to ensure good bond, and throw the coarser stuff in after."

_Second Note by Major Baylay, Peter Maritzburg, Natal, South Africa_

"I have completed a small building, and though weather conditions have been as bad as possible, it is sound and very satisfactory.

"In my opinion, pise-building should not be attempted in the rainy season in Africa. Earth contains too much moisture, and the power of the sun dries it out too quickly and causes cracks.

"_Re_ plastering. I covered the outside and inside with a mixture of 6 earth, 2 sand, 1 blue (Hyd.) lime, the earth being the red, rather 'fat' earth found everywhere, and the same stuff the house is built of. It is put on thin with a trowel, after damping the wall. When it dries and cracks, rub all over with a sacking pad covered with the plaster mixture, but wetted to a thin cream consistency. It may sound an odd method, but the natives do this work well, and the result is as good as one can wish for. You can put tar or any wash (No. 6) on this."

[Headnote: Soils]

SOILS

Were it not for the fact (often somewhat embarrassing) that soil quite incapable of making good pise will none the less produce enthusiastic pise-builders, a warning as to the vital importance of the earth being really suitable might seem superfluous.

The author has found some of the staunchest champions of pise-building living on and valiantly struggling with stiff glutinous clay and almost pure sand.

Even the most vigorous optimism can achieve little under such adverse conditions unless soil-blending be resorted to, and even so, pise-building begins to lose points in the matter of economy directly complications of this sort are introduced.

Fortunately, however, England is well off in the matter of pise soils, the red marls being amongst the very best.

A study of the country, or, failing that, of the geological maps, will reveal a great tract of this earth extending diagonally right across England, from Yorkshire down into Devonshire, where it ends conspicuously in the beautiful red cliffs about Torquay.

There is a large area of the stuff in the Midlands, notably in Warwickshire, with lesser patches here and there about the country.

Second only to the red marls come the brick earths, which, fortunately, are also widely distributed.

"Brick earth" is merely clay that has been well weathered and disintegrated under the action of wind, rain, frost, and organic agents, the sulphides having become oxides, and what was a cold intractable slithery mass having become merely a "strong" and binding earth.

It is probable that even stiff clay, if dug in the summer or autumn, and left exposed for a winter, would prove sufficiently reformed to be quite amenable for pise building in the spring.

After the marls and the brick earths there is an endless variety of soils that will serve well for pise-building--some, of course, better than others, but all, save the extremes (the excessively light and the excessively clayey), capable of giving good results under proper treatment.

Before putting pise construction actually in hand, however, the intending builder will do well to submit samples of his earth to some competent authority, that they may receive his blessing.

A fistful taken from a depth of 9 in., and another from say 2 ft. below the surface, should give sufficient evidence as to the soil's suitability or the reverse.

III

_CHALK_

Sec. I. GENERAL

Chalk, as a source of lime, has always been of high importance to builders, and, until improved transport brought alien materials into its old preserves, chalk was in general use for walling in the form of roughly squared blocks.

Chalk again forms the basis of a compost that, used in the form of a stiff paste, has been largely employed for building from the earliest times down to the present.

"Pise de Craie," or chalk consolidated by ramming within a casing, is a form of building that has been long held in high repute in France and elsewhere, but which has only recently been given a serious trial in England.

Chalk in all these forms, if fairly dealt with and reasonably protected from the weather, is a most amenable and satisfactory material to build with.

The last-named method particularly seems to promise results that should satisfy the most exacting critics of the unconventional, as it assuredly does those who inhabit the cottages so constructed.

The several systems of chalk construction are fully dealt with in the pages that follow.

_Chalk Compost: Historical._--At the Ancient British village on West Down, Chilbolton, some five miles south of Andover, delving archaeologists have brought to light undeniable fragments of chalk "Daub," with the wattle marks still clearly showing upon them.

This discovery is chiefly of academic interest, though it is a pretty refutation to those who regard any building material save brick and stone as "new-fangled," and it should also serve to hearten the doubters and the timid amongst us who seek historic sanction for any departure from current building practice.

_Composition and Uses._--In the Andover district Chalk Compost or "Chalk Mud," as it is called locally, is prepared and used as follows:

The chalk is dug out in the autumn, and the frost allowed to play on it during the winter. In the spring building starts, and the weathered chalk is spread all around the outside of the walls. Straw is sprinkled on it and it is then well trodden, usually by the workers, but sometimes by horses. Sometimes chopped straw is added, sometimes unchopped straw is sprinkled on. The quality of the walls depends very largely on the preparation--that is, in getting the mud to the right consistency--and the old hands know by experience when it is ready.

The compost is lifted on the wall by a fork and another man stands on the wall and treads it in. It is then chopped down straight with a spade. Some of the naked walls at Andover show traces of the courses, which are usually something under 2 ft. in height.

Where a course has to be left unfinished it should be ended with a diagonal ramp so as to splice in with the work that follows.

Some of the old builders seem to have been somewhat catholic in their conceptions as to what constituted "chalk," and vague patches of earth, loose flints and other stray substances not infrequently mar their work and sometimes seriously reduce its strength.

As a general rule, the finer the chalk the stronger and more durable is the walling.

What is aimed at is a conglomerate of small chalk knobs cemented together by a matrix of plastic chalk and straw, the whole forming as dense a mass as possible.

Grinding in a mortar-mill would probably reduce all the chalk to an amorphous powder, which would not be desirable, and in any case such mechanical mixing is quite unnecessary.

Building by ramming the moist compost between timber shutterings does not appear to have been practised in the past, though there is nothing against the method except its tendency to delay the drying out.

The drying of each course takes several days, depending on the weather. A course is usually laid right round the building. It must be covered up at night in case of rain, and when it is hard another course is laid on, and so on till completion. The aim is to build during the summer and autumn, and when the moisture has dried out, to render the exterior.

Where brickwork is used with chalk compost it is generally bonded in in the ordinary way, but block-bonding the depth of a chalk course is a better way of doing it.

The exterior corners of chalk buildings are the vulnerable points, and these should therefore be well rounded off.

_Timber._--In the old work nothing seems to have been done to prevent woodwork built in to the compost from decaying, though in many cases it has survived surprisingly. In any new work, however, proper ventilated air-spaces should be contrived or the timber ends treated with some preservative.

The door and window frames are fixed to fairly large pieces of wood built in across the thickness of wall, and other woodwork is fixed to wood blocks built in in a similar way.

Picture-rails should be provided in all rooms, as chalk walls are apt to flake and chip if nails are driven into them.

Lintels are usually of wood, and when plastering is carried down over these some form of key must of course be provided to hold it.

[Headnote: Winter Work Barred]

_Frost._--New work must not be exposed to frost or there will be danger of collapse, and winter work is barred out for this reason.

_Repairs._--Chalk compost walls are not easily repaired in that material, and bricks are generally used, well bonded in.

_Chimneys._--Chimneys, too, are usually of brick, though there would seem no reason against the flues being carried up in chalk, especially if clay pipe linings were used.

The chimney-stacks above the roof might well be built in flint, the corners being rounded off in deference to the peculiarities of the material.

_External Rendering._--It is of the first importance that a good weather-tight skin be maintained, and many old buildings have suffered through neglect of this precaution.

The rendering was often of the poorest quality, more mud than lime, and the constant repairs that the indifferent materials necessitated has resulted in many of the old cottages becoming patchworks of variegated plaster blotches, when not whitewashed over, which give an impression of dilapidation by no means warranted by the facts.

_Rendering._--Given a good skin, however, of cement or cement and lime, a chalk conglomerate wall will last indefinitely. So vital is the skin that it is as well to put it on in two good coats--rounding off all the corners and finishing it either with slap-dash or rough from the wooden float.

Also, to ensure its proper adhesion throughout, wire-netting may be used as reinforcement--being secured to the face of the chalk wall by means of cross netting or wires laid on the wall as the building rises.

If the netting be of a fine mesh it also serves as an absolute barrier to vermin, though pounded glass incorporated in the base of the wall is equally effective.

_Strength._--Provided the wall has dried out thoroughly, any of the ordinary loads occurring in a two-storied house can be borne with ease.

Chalk conglomerate walling, however, has no great lateral strength, and it should not be asked to stand up to thrusts.

The roof, therefore, must be well tied, and should sit on the building merely as a lid.

_Roof._--Though thatch is the traditional roofing material of chalk cottages, any other will serve that is permanent and good of its kind.

The only special demand that chalk walls make is that the eaves shall be generously overhung for their better protection from the weather.

Where, in later years, the boldly projecting thatch has been thoughtlessly replaced by a slate roof with meagre eaves, or with none at all, the walls have suffered accordingly.

[Headnote: Garden Walls]

_Garden Walls._--A chalk garden wall must be afforded just as much protection as the wall of a house and on both sides.

The hat with which it is provided is of the highest importance to the health and longevity of the walling.

Examples of garden wall copings are given in the sketches shown below.

_House Walls._--Chalk conglomerate walls rarely exceed 18 in. in thickness, and are usually the same upstairs as down.

A plinth of the same thickness as the chalk wall it supports is usually carried up 6 in. to 18 in. above the ground level in rubble-work, flint, or brick, being known as the "Underpin Course." Any of the stock damp-courses are suitable, but they must be well and truly laid, as damp feet are nearly as deleterious to a chalk wall as a leaky or inadequate hat.

No special tools are required for this method of building, an ordinary farm fork for lifting and a spade for the final chopping down of the wall faces being all that are necessary.

A house built during the summer is usually fit for occupation the same autumn.

_Old Examples._--Those who may wish to see buildings in chalk conglomerate, both old and new, would do well to visit some such typical chalk district as that lying about Andover in Wiltshire.

It should, however, be constantly borne in mind that most of the old cottages were somewhat unscientifically erected by their original jack-of-all-trades occupiers, that damp-courses and Portland cement were unknown, and that the advantages of proper ventilation and the causes of dry-rot were discoveries yet to be made.

Secondly, a large number of these cottages have been sadly neglected either recently or in the past, and they bear the disfiguring marks of their ill-treatment upon them now.

But a chalk cottage that is well found in the beginning, and that is reasonably well cared for subsequently, has nothing to fear from comparison with cottages built in the most approved manner of the more fashionable materials.

Mr. James Thorold gives the following particulars of a block of three chalk cottages recently built for Sir George Cooper on his estate at Hursley, near Winchester:

"The chalk walling was done by Messrs. A. Annett and Son, of Winterslow, near Salisbury, where this method of building has been kept alive from olden days. It consists of working up the soft upper strata of the chalk by putting a bed of it 4 ft. 6 in. thick on the ground, watering and treading it to a sticky consistency with the feet, working in shortish straw at the same time. When thoroughly mixed by the builder's mate, he lifts up a forkful to the builder working on the wall immediately above him, the latter catches the chalk, dumps it down on the top of the wall, building an 18 in. course all round. As soon as the weather has dried this sufficiently he goes round with a sharp spade squaring up both sides of the wall. As this work is greatly dependent on the weather it is well if the men have other work to fall back on, and that building operations should be commenced in the spring or early summer. The wall is built 18 in. thick to the first floor joists and 14 in. above. Chalk in itself being very absorbent of moisture, the usual plan is to render the outside of the wall with a lime mortar, which, however, requires renewal every few years. To obviate this we fixed with long staples 1-1/4 in. mesh wire-netting over the outside surface of the wall to give a reinforcement for a rendering of hair mortar and cement gauged in proportion of 1 to 2 respectively, and left rough from the trowel. This rendering was done at a cost of 3s. 3-1/2d. per square yard, which is a substantial addition to the cost of the walling, but so far there is no sign of a crack or hollow place behind it, and the cottages have kept very dry. The walls were finished off with a limewash containing Russian tallow and copperas.[9]

[Footnote 9: See recipes for Whitewash in Appendix (I).]

[Headnote: Cost of Three Cottages]

"As regards the cost of this block of three cottages, the result is obscured by the fact that tall chimney-stacks with ornamental bricks and appropriate foundations were built and reinforced leaded lights were used in the windows to keep the building in character with the other cottages on the estate, but at the time we estimated that the chalk walling saved a sum of L54 as against the amount we should have had to have spent in carrying out the building with bricks made on the estate, and this had to include lodging money and profit, the builders being independent men. The ornamental chimney-stacks were put in for the sake of appearance, flues built up in the chalk being entirely satisfactory and fireproof. The foundations are either flint or brick with a slate damp-course.

"I consider that for a chalk country this method of building has many advantages.

"(1) It saves cartage.

"(2) It can be carried out by a skilled labourer who can be
otherwise employed during unsuitable weather.

"(3) No fuel is required as in burning bricks.

"(4) If a suitable rendering is employed to keep it weatherproof,
and a good damp-course on the foundations, the cottages are nice
and dry and keep an equable temperature, chalk being a good
non-conductor.

"Sir George wonders if any method could be devised by chemical means to harden the chalk and make it weatherproof; if this could be done it might save the expense of the cement rendering."

CHALK CONGLOMERATE

From _Country Life_, February 23rd, 1901:

"Soft chalk is practically mud, yet Dr. Poore, one leading authority on rural hygiene, had his model hygienic cottage built with it at Andover, just outside the boundaries, in order to escape the tyranny of the bye-laws. In several other places this material has been used time out of mind.

"The white cottages on the Wiltshire Downs are as good as any in England."

THE WINTERSLOW COTTAGES

From _Country Life_, April 6th, 1901:

"The white chalk cottages of the scattered straggling village are found in every sort of position. They must not be confounded with the cottages of rock chalk at Medmenham. You might almost call them mud cottages.

"The house is generally both planned and constructed by the owner.

". . . The soil is only a few inches deep, soft chalk lies close to the surface and can be dug out with a spade. This is a very suitable material in the district and costs nothing but the labour of digging. . . .

"On the downs there is a constant lack of water; that which falls in the shape of rain is therefore very precious, and in some cases is indeed the only kind available. But a large tank or artificial well is needed to contain it, and the pit from which the chalk is dug out can be made to serve the purpose. . . . One was made watertight by means of a lining of concrete, and held enough water to keep the family going through all the dry season.

"In another house . . . the chalk-pit had been utilised to form a large and convenient cellar. . . .

"Most of them (the cottages) . . . are on two floors, with parlour, kitchen, back kitchen and so forth on one, and the bedrooms on the other. In the preparation of the chalk, the method followed is that of treading it into a kind of rubble, and adding a proportion of straw and a small quantity of lime.

[Headnote: Expensive Scaffolding Avoided]

"There is a local builder who will run up the shell of a house for a matter of L100, more or less, according to its size. . . . Most of the cottages are literally hand-made. A skilful architect who visited the Winterslow cottages felt sure that boards must be used to keep the walls straight, but he was wrong. The chalk is shovelled up and the walls are kept straight without line or plummet. No expensive scaffolding or machinery is employed. Yet the walls come out beautifully in the end, the colour being an exquisite soft white. They are about 18 in. thick, and the slowness of their construction has one good effect, it gives them time to dry. No point is of more importance than this. It is advisable not to put on any rough-cast, plaster, or paper for at least twelve months, as doing so will prevent the moisture from exuding. One or two of the little cottages were slightly damp, but the majority were as dry as tinder. The thickness of the walls helps to render the cottage more comfortable, to make it cool in summer and dry in winter.

"One word should be added in regard to soft chalk as a building material. Where it can be obtained in the garden at a few inches depth, and especially where the cottager is his own architect and builder, it can be most heartily recommended, but there are obvious objections to its transportation to districts where it is foreign.

"The village itself is a very homely and irregular one without a single dwelling of any pretence. The country lying adjacent to Salisbury Plain consists of broken, sparsely peopled downland, and very ornate or finished cottages would be out of keeping, but they would not look so well copied in a very rich, heavily timbered country."

RATS AND CHALK

_Note._--Conglomerate chalk is, like cob, vulnerable to the attacks of a really determined rat.

The outer defences provided by the exterior rendering can be backed up by the mixing in of broken glass or sharp flints with the substance of the wall, where such attacks are likely.

[Headnote: Block Chalk]

BLOCK CHALK

"Chalk" is a term somewhat loosely used to denote the soft white limestone--the "_Creta Scriptoria_"--that is cousin to Marl on one side and to Ragstone on the other.

In its purest form chalk consists of over 95 per cent. of carbonate of lime in the form of fine granular particles held together by a calcareous cement, its organic origin being clearly traced in the remains of the minute sea creatures with which it abounds.

Hewn blocks of chalk have been used for walling and vaulting from immemorial times, and, where not exposed to direct erosion by the weather, remain to this day as clean-cut as when they were first quarried and a very great deal harder.

The filling in of the great vaults at Salisbury Cathedral and in the Bishop's Palace are of chalk, whilst innumerable lesser buildings of more or less antiquity still remain to us as monuments to the excellence and durability of this stone.

Chalk, too, was often used in combination with flint or brick to build the engaging chequer-work walls that embellish so many downland villages.

At Medmenham there are cottages both old and new of hewn rock chalk, and both the Berks and Bucks banks of the Thames have many buildings to show of this beautiful material.

Amongst present-day architects Sir Edwin Lutyens was the first to give hewn chalk an opportunity of showing its quality in serious architecture, Marsh Court in Hampshire being an instance of more than local celebrity.

In the great walls at the Bishop of Winchester's palace, Farnham Castle in Surrey, the old builders appear to have used bricks, limestone and chalk proper, according as the several materials were delivered, quite indifferently, and with results altogether delightful.

Not all chalk is suitable for building, that near the surface being often far gone in decay and much too friable for such a purpose.

Even when apparently sound blocks have been gotten they are not infrequently found to be crossed in all directions by planes of weakness along which they are apt to fall to pieces in the handling.

From this cause the "waste" is sometimes considerable.

The well-known building "stones" from the quarries of Beer, Sutton, and Tottenhoe in Devonshire are really chalk, but in a form not readily distinguishable from ordinary free-stone.

The longer that chalk blocks are kept to dry before building-in the better, and the sun and wind of at least a year should be allowed free play upon them to dry out their natural sap and render them "frost-proof."

During the drying-out process the chalk should, if possible, be protected from the rain.

For years after being built into the walls of a house, chalk will continue to dry and harden.

But it is essentially a somewhat porous material, and will quickly revenge itself on those neglecting its just demands for a sound roof and a proper damp-course.

In exposed situations new chalk walling is liable to allow the penetration of moisture under the pressure of the wind unless a cavity is provided or unless the surface is treated with a silicate or other "vitrifying" fluid.

Chalk, however, has one shining virtue in common with its great antithesis--it improves mightily with keeping.

Chalk walls sometimes have youthful vices in the way of porosity that entirely disappear with advancing years through the closing up of the surface pores, which eventually makes a cavity and inner lining superfluous.

IV

_UNBURNED CLAY AND EARTH BRICKS_

SUN-DRIED BRICKS

The use of sun-dried bricks in this country, is, for no very apparent reason, almost entirely restricted to East Anglia. There it has been used for generations with entirely satisfactory results.

Mr. Skipper of Norwich writes of the material as follows:

* * *

"Who, travelling from Norfolk to London, whether by the Ipswich or Cambridge line, has not noticed the numerous colour-washed or black (tarred) cottage, farmhouse and agricultural buildings scattered practically all along the countryside? Some of these are of studwork and plaster, some of wattle and daub, but many are built of clay made up into lumps, sun-dried, and built into the walls with a soft clay-mixture as mortar. No lime _need_ be used, though sometimes it is mixed with the clay mortar. The preparation, digging, exposure and mixing with short straw are similar to the Devonshire 'cob' work, but in these parts the worked clay is thrown into moulds, and lumps are formed of, say, 18 in. by 12 in. by 6 in., or 18 in. by 9 in. by 6 in. for large sizes, and for inside walling or backing to brick-faced walls, 18 in. by 6 in. by 6 in. The walls, naturally, are rough in texture and the joints are generally stopped up and besmeared with a thin coating or almost a wash of clay. This coating sometimes has lime mixed with it, but it is not necessary. This is all that is needed to complete the walling, and there is a building--a malting, that any one can see at Tivetshall Station on the Ipswich line, about 200 ft. long, 45 ft. or 50 ft. wide and three floors high, built of lumps 18 in. by 12 in. by 6 in.--that has stood the weather and weight of its roof for forty years built in this way; 12 in. is the thickness of its walls. A further stage in finish is to give the walls two or three coats of coal tar, but it is not essential, though desirable where stock are kept, as cattle are rather fond of licking the clay, and they do not use their horns much when walls are tarred. The highest finish in this work is to cast sand on the last coating of tar before it is quite dry, and then to colour or whitewash on this. This accounts for the variety of colourings seen in these buildings, some even of a kind of pink or red; while some yellow or buff, beside the white and the black or tarred buildings, and all huddled together or standing apart, whether covered with thatch or red pan or flat tiles, look remarkably in harmony with their surroundings. These lump walls are, of course, built on a base of brickwork, about 18 in. or 2 ft. high, to keep them free from damp. This kind of walling can be built for _at least_ 15 per cent. or 20 per cent. cheaper than ordinary 9 in. brickwork. Thin as these walls are compared with those of 'cob' houses, they are noted for being warm in winter and cool in summer. When suitable clay is procurable a local builder almost invariably uses clay lumps when building a house for himself, though to gratify a whim perhaps, he will case the outside walls--especially the front next the street or road--with brickwork. But clay lumps he carefully reserves for inside walls and weight-carrying linings to the outside walls, bonding the two together very much in the same way as two 4-1/2 in. 'cavity walls' are bonded. I am not suggesting that this walling is as interesting artistically as 'cob,' but I do suggest it is a practical, sensible and _dry_ walling, and if properly done it will 'last for ever,' as a local builder repeatedly said to me when speaking of it. One can easily see why the cost is light--the sun and the winds do the drying in the spring months, and no coals are required, and also the clay is often found on the building site, hence no cartage. Actual building work naturally goes quickly, as the lumps are large. There is another important point to notice. One may see a building complete with its roof on and occupied by its tenant while still awaiting an outside casing of brickwork to be built round it, either with a view to greater protection or for the mere vanity of the owner, for while thus left unprotected the lump walls take no harm from even winter exposure. Now to be quite practical in these extremely practical days, I venture to suggest that the use of clay lumps at least for inside walls and linings of outside walls would be an immense boon to the numerous cottage-building schemes now being projected. We must not forget that comparatively few bricks will be available this year, while the cottages are wanted at once. Can these few bricks be better used than by forming foundations and chimneys for the clay-lump walls of these cottages? I think not. The cottages could, of course, be occupied in the late summer or autumn of this year, and next year when bricks will be more plentiful perhaps the brick casings could be added, if brickwork _must_ complete them. I make this strictly utilitarian suggestion solely to meet a very urgent and deep national need. Personally, I prefer the sight of a cottage built and finished in the old-established method of the locality. Unskilled labour only is required, working under intelligent supervision, hence immediate employment for a great number of men would be provided."

[Headnote: Use for Unskilled Labour]

* * *

The use of sun-dried bricks for the interior partitions of cob and pise cottages is worth consideration, as the nature of these materials demands a thickness of wall which is too wasteful of space to be acceptable in mere partitioning.

Of the strength of clay-lump walls, there is no question. It was recently necessary to cut a new doorway in the old clay-lump wall of a large traction-engine garage, and the blocks removed were thrown into a heap upon the ground.

The clay happened to be needed for other purposes, for which it had first to be broken up.

Ordinary hammers proved entirely ineffective, and it was not until heavy sledges were used that the lumps could be smashed.

The tractor-house in question is a large building some 25 ft. by 100 ft., carrying a heavy roof and constantly subjected to vibration by the coming and going of the tractors.

The walls are only 12 in. thick, without piers or reinforcements of any kind, and yet the whole building, which is 26 ft, high at the gables, is as perfect to-day as when first erected some twenty years ago.

In the same town as this tractor-house, East Harling in Norfolk, is a council school built of clay lump (converted from the old Corn Hall), apparently not a pin the worse for a century of hard wear.

Near by there are a number of private houses built of the same material, some of them reputed to be upwards of 200 years old and certain of them having considerable architectural merit.

[Headnote: "Substantial and Cool"]

(_Extract from "The Farmers' Handbook," issued by the Department of Agriculture, New South Wales, 1911_)

+"Adobe," or Sun-dried Bricks+

"As their name implies, these buildings are constructed of sun-dried, but unburnt bricks. For buildings of this character, material like clay, which is unsuitable for pise-work, can be used. The bricks are made in a wooden mould, and are 16 in. long, 8 in. wide, and 6 in. thick. A man can mould about 100 per day. They are laid in a similar manner to other bricks, the mortar used being wet loam, or even the material of which the bricks are made. The cost of making and laying is estimated at about 15s. per 100. Buildings constructed of these bricks are substantial and cool, and very similar in character to pise buildings.

"A school-house built of these bricks eighteen years ago by Mr. Nixon, of Reefton, is still in an excellent state of preservation; in fact, little, if any, the worse for wear, despite the fact that walls are unprotected by verandahs or overhanging eaves. During its existence it has had, first one coat of oil-paint, and later a coat of coloured limewash."

* * *

"Clay lump," then, is one of the many good old building methods that needs no proving, but only revival and perhaps improvement.

APPENDIX

I

WHITEWASH

Whitewashing has been frequently referred to in the foregoing pages as the most suitable treatment for the exterior of chalk and earth buildings.

There is, however, a certain prejudice against lime-whiting amongst both owners and occupiers, owing to the frequent renewal that its adoption usually implies.

With a view to removing this drawback from a treatment otherwise so effective, the following recipes are suggested as improvements on the usual practice.

Ordinary whitewash is made by slaking about 10 lbs. of quicklime with two gallons of water.

The following recipes are taken from "_White Paints and Painting_" (Scott), and are reliable:

(1) "_Factory" Whitewash (interiors), for Walls, Ceilings, Posts, etc._:

(_a_) 62 lbs. (1 bushel) quicklime, slake with 15 gallons water.
Keep barrel covered till steam ceases to arise. Stir occasionally
to prevent scorching.

(_b_) 2-1/2 lbs. rye-flour, beat up in 1/2 gallon of cold water, then
add 2 gallons boiling water.

(_c_) 2-1/2 lbs. of common rock-salt, dissolve in 2-1/2 gallons of hot
water.

Mix (_b_) and (_c_), then pour into (_a_), and stir until all is well mixed. This is the whitewash used in the large implement factories, and recommended by the insurance companies. The above formula gives a product of perfect brush consistency.

(2) _"Weatherproof" Whitewash (exteriors), for Buildings, Fences, etc._:

(_a_) 62 lbs. (1 bushel) quicklime, slake with 12 gallons of hot
water.

(_b_) 2 lbs. common table salt, 1 lb. sulphate of zinc, dissolved
in a gallon of boiling water.

(_c_) 2 gallons skimmed milk.

Pour (_b_) into (_a_), then add the milk (_c_), and mix thoroughly.

(3) _"Light House" Whitewash_:

(_a_) 62 lbs. (1 bushel) quicklime, slake with 12 gallons of
hot water.

(_b_) 12 gallons rock-salt, dissolve in 6 gallons of boiling water.

(_c_) 6 lbs. of Portland cement.

Pour (_b_) into (_a_), and then add (_c_).

* * *

_Note._--Alum added to a lime whitewash prevents it rubbing off. An ounce to the gallon is sufficient.

Flour paste answers the same purpose, but needs zinc sulphate as a preservative.

The following are from "_1,000 More Paint Questions Answered_":

(4) _Durable Whitewash for Outside Use._--A whitewash that will not rub off or wash off in rainy weather can be made by mixing one half-pint of flour to a batter with cold water, then stirring into this boiling water until it becomes a thick paste.

While still hot it is poured into a pailful of ready-made lime whitewash and well stirred in.

(5) Another simple method is to add to 2 gallons of ready-made lime whitewash one half-pint each of molasses and table salt. Must be stirred frequently while being used.

_Whitewash for Exterior Surfaces._--A formula for a durable whitewash for out-buildings of rough lumber. The following is reprinted from "_Popular Mechanics_":

(6) Place 1 bushel good fresh lime in a barrel with 20 lbs. beef tallow; slake with hot water and cover with sackcloth to keep in steam. When the lime is slaked, the tallow will have disappeared, having formed a chemical compound with the lime. Dry colours may be added to produce any tint desired.[10]

[Footnote 10: Experiments and tests carried out for the author
by the Department of Scientific and Industrial Research place
this receipt at the head of the list.]

It is better to add colour before slaking the lime, but if this is not feasible mix the colour with alcohol and add it to the strained whitewash. Thin to easy flowing consistency with clear water.

[Headnote: Distempers and Limewashes]

_Cold Water Paint that will stand the Weather._--A formula for making a white outside coating that will resist the action of the weather and remain hard even under the influence of moisture and rain. Experiments with different brands of cold water paints have proved failures.

A really effective cold water paint, in order to resist the elements and remain white, should contain a white pigment of good body and some oil in addition to the water, and with this purpose in view the following is suggested:

(7) To make 100 lbs. of such paint, mix 10 lbs. white, pure in oil, with 10 lbs. bolted whiting, 8 lbs. raw linseed oil, 6 lbs. soft soap (made with potash), and 26 lbs. soft water.

One quart of pale copal varnish will improve the preparation. The formula given is of the right consistency to apply on dressed lumber with the brush. For application on rough lumber or with the spraying machine it requires more thinning with water and varnish.

The following is taken from Pearce's "_Painting and Decorating_":

(8) A London recipe for distemper has the following proportions: 4 "balls" whiting, 2 lbs. Young's patent size, and sufficient water to cover the whiting.

(9) A Scotch distemper is described as: 12 lbs. whiting, size as given previously, 2 ozs. alum, 2 ozs. soft soap. It is very fast, for passages, schools, etc. Tinting colours for limewash should be restricted to ochres, umbers, lime blue, lime greens, charcoal or lamp black, and earthy reds (as Venetian).

(10) External limewash for farm buildings, etc., may be made as follows: Lime, 1/2 bushel, slaked with 1 gallon of milk and remainder of water, 1 lb. salt and 1/2 lb. sulphate of zinc to make it withstand the weather.

Experiments with and practical tests of these and other kinds of whitewash are being carried out, and the author hopes that he may find opportunity at some later date of announcing the results obtained.

[Headnote: Local Materials]

II

THE IMPORTANCE OF USING LOCAL MATERIALS

(_Extract from "Country Life," November 9th, 1918_)

300,000 COTTAGES WOULD ENTAIL THE TRANSPORT OF 60,000,000 TONS
OF MATERIAL

In carrying out any considerable scheme of house building two difficulties will have to be met. The first arises from the scarcity of building material; the other from the cost and difficulty of transport. These, to some extent, can be obviated by the use of local material, which is to be commended on other grounds as well. Local material fits into the character of the neighbourhood in which it is found and maintains its traditions.

Very few people realise the bulk of materials, and in order to help them the following statement has been prepared to show the materials needed for each cottage and the total for 300,000 cottages:

Materials. Weight.
Per One Cottage. Per 300,000.
Tons. Cwts. Qrs. (Tons.)
Ballast, sand, gravel 78 17 0 23,655,000
Lime 5 18 0 1,770,000
Cement 12 8 0 3,720,000
Bricks 85 0 0 25,500,000
Slates for D.P.C 0 10 2 157,500
Chimney-pots 0 0 3 11,250
Tiles 7 2 2 2,137,500
Carcassing timber 7 0 0 2,100,000
Complete joinery timber 1 12 0 480,000
Cast-iron rain-water goods and sundries 0 9 0 135,000
Stoves, copper, ash-bin, etc. 0 5 2 82,500
Nails, screws, etc. 0 1 2 22,500
Hair for plaster 0 1 0 15,000
Lead flashings, etc. 0 2 1 33,750
Sink, waste pipes, draining boards, etc. 0 2 1 33,750
Sanitary goods 0 1 0 15,000
Whitening, distemper and paint 0 3 1 48,750
--------- ----------
Total 199 14 2 59,917,500
--------- ----------

It will be seen that to carry out the scheme for 300,000 cottages a total of close on 60,000,000 tons of material will have to be shifted. In addition to that, it must be remembered that the cost of material is very small in comparison with that of building. This will be apparent from an analysis of the items employed for actual cost and the percentage which that cost bears to the total cost.

Cottages erected 1912 (semi-detached): total interior area of cottage, 772 ft. super, (parlour, kitchen, scullery and three bedrooms, coal and W.C.):

Per House.
No. Item. Actual Cost. Per cent. of
Total Cost.
1. Sundries 8 2.66
2. Foundations 16 5.28
3. External and party walls (_a_) 77 25.41
Windows and doors (_b_) 23 7.59
4. Internal partitions 36 11.88
5. Ground floor 18 5.94
6. Upper floor 22 7.26
7. Roof and rain-water goods 34 1.22
8. Chimney and fireplaces 30 9.90
9. Sanitary fittings, water supply and
drainage 19 6.27
10. Staircases 11 3.63
11. Fittings 6 1.98
----
Total L300

These facts help to clarify the problem. The weight of the building materials required for an ordinary cottage with living-room, parlour, scullery, three bedrooms, etc., the house containing cubic contents of about 11,500 ft., would come approximately to 200 tons per cottage; and even assuming that there is only an average transport of fifty miles, this would give 10,000 ton-miles per rural cottage, which is taking it at a very low average. In each cottage the weight of the brickwork represents about 42 per cent. of the total weight. It is, therefore, apparent that every effort should be made to lessen the transit of materials required for the external walling. If, on the other hand, local materials are employed, this carriage would be saved and a great economy effected. Even if this utilitarian consideration were not so important as it is, the desirability of making all possible use of local materials is very great from other points of view. It would stimulate local interest in building and, in addition to retaining the traditions of the district, give greater hope of retaining and maintaining the proper architectural aspect of our villages.