The public buildings are mostly constructed of broken stone and mortar, plastered outside and covered with red tiles, but the common dwellings are generally constructed of tapiarough trellis-work walls filled in with mud.
The potting must be done very firmly, using turfy loam with which a little mortar rubble has been mixed.
And put together without any mortar, but sustained by their own weight, are built all the massive walls and other structures on the east side of the island.
Sometimes their homes are mere huts of turf, or of clay tiles, with mortar made from lime and clay or cow-dung.
Those pieces are connected at theii joints or surfaces of mutual contact, either by simple pressure and friction (as in masonry with moist mortar or without mortar), by pressure and adhesion (as in masonry with cement or with hardened mortar, and timber with glue), or by the resistance of fastenings of different kinds, whether made by means of the form of the joint (as dovetails, notches, mortices and tenons) or by separate fastening pieces (as trenails, pins, spikes, nails, holdfasts, screws, bolts, rivets, hoops, straps and sockets.
The character of the ancient citadel wall at Athens, already mentioned, has given the name "Pelasgic masonry" to all constructions of large unhewn blocks fitted roughly together without mortar, from Asia Minor to Spain.
If 127 parts of iodine, which is an almost black solid, and loo parts of mercury, which is a white liquid metal, be intimately mixed by rubbing them together in a mortar, the two substances wholly disappear, and we obtain instead a brilliant red powder quite unlike the iodine or the mercury; almost the only property that is unchanged is the weight.
In times of scarcity the Norse peasant-farmer uses the sweetish inner bark, beaten in a mortar and ground in his primitive mill with oats or barley, to eke out a scanty supply of meal, the mixture yielding a tolerably palatable though somewhat resinous substitute for his ordinary flad-brod.
Ouro Preto has several historic buildings; they are of antiquated appearance and built of the simplest materials - broken stone and mortar, with an exterior covering of plaster.
The granular tufa is useless for either purpose, containing too much earth to be employed in making mortar, and being far too soft to be used as stone for building.
Of rough materials, such as broken bricks or mortar rubbish, over which should be placed a layer of rough turf with the grassy side downwards, and then the good loamy soil to form the border, which should have a depth of about 2 ft.
The city is characteristically Portuguese in the construction and style of its buildings - low, heavy walls of broken stone and mortar, plastered and coloured outside, with an occasional facing of glazed Lisbon tiles, and covered with red tiles.
The setting of the mortar is due to the drying of the lime (a purely physical phenomenon, no chemical action occurring between the lime and the sand).
Ordinary mortar), are used for the latter purpose is their great mechanical strength.
The houses are built of stone and mortar, and above the thatched straw roof which surmounts the doublestoreyed buildings the square water-tower rises gracefully.
For this purpose Koch ground up tubercle bacilli in an agate mortar and treated them with distilled water until practically no deposit remained.
Is probable, however, that, all things considered, Materials random rubble in which the flattest side of each block of stone is dressed to a fairly uniform surface, so that it may be bedded as it were in a tray of mortar, secures the nearest approach to uniform elasticity.
All stones must be beaten down into their beds until the mortar squeezes up into the joints around them.
In the best examples this has been secured by bedding the stones near to the water face in somewhat finer mortar than the rest, and sometimes also by placing pads to fill the joints for several inches from the water face, so that the mortar was kept away from the face and was well held up to its work.
On the removal of the pads, or the cutting out of the face of the mortar where pads were not used, the vacant joint was gradually filled with almost dry mortar, a hammer and caulking tool being used to consolidate it.
In the case of the Neuadd dam this difficulty was met by deliberately omitting the mortar in transverse joints at regular intervals near the top of the dam, except just at their faces, where it of course cracks harmlessly, and by filling the rest with asphalt.
The masonry is described by Mr Schuyler as " a rough uncut granite ashlar, with a hearting of rough rubble all laid in cement mortar and gravel."
This, if the dam had been thoroughly well constructed, either with hydraulic lime or Portland cement mortar, would have been easily borne.
The quicklime as quarried from the bluffs slakes perfectly, and with sand makes a fairly good mortar, without calcination or other previous preparation.
A feature of the upland districts is the total absence of hedges, and the substitution of limestone walls, put together without any mortar or cement.
Before 1405 the mortar used in Venice was made of lime from Istria, which possessed no hydraulic qualities and was consequently very perishable, a fact which to a large extent accounts for the fall of the Campanile of San Marco.
The Varga Mozsar, or great mortar, which sixty horses could scarce move from its place, and a ballistic machine invented by Matthias which could hurl stones of 3 cwt.
Thick, and formed of a core of rough rubble cemented together with mortar (containing much coarse gravel) of extraordinary hardness and tenacity, and a facing for the most part of stone - Kentish rag, freestone or ironstone - but occasionally of flints; about 2 ft.
In height, but towards the top of the mountains they are sometimes as much as 15 or 18 ft.; they are built entirely of rough stone without mortar, and I reckon that on an average each wall retains not more than twice its own height in breadth, and I do not think I saw a single break in them unrepaired."
As the roads advance other pillars are driven through in the same manner, the passages first made being closed by stoppings of broken rock, or built up with brick and mortar walls, or both.
In smooth-bore days the term mortar meant a piece of ordnance of a peculiar shape resting on a bed at a fixed angle of quadrant elevation of 45°.
In flat forms of masonry floor construction the level of its bottom is placed somewhat below the bottom of the " I " beams and girders, so that when it is plastered a continuous surface of at least an inch of mortar will form a fire-proof protection for the lower flanges of the beams and girders.
The line of the city wall, of rough rectangular blocks of stone without mortar, may still be traced all round the coast, with two gates, one on the north towards the mole, which is still in part preserved, and one on the south.
The coating of lime or mortar is soft and brittle, and consequently the young oysters can easily be detached with a stout knife.
There are, moreover, traces of still more primitive walls, built of rude small stones placed one upon the other without mortar, which are in character earlier than those of Tiryns, and have their parallel in the lowest layers of Hissarlik.
The older buildings are of the Portuguese type, usually plain, low and heavy, constructed of broken stone and mortar, and plastered and coloured on the outside.
Subsequent hardening of the mortar is caused by the gradual absorption of carbonic acid from the air by the lime, a skin of carbonate of lime being formed; but the action is superficial.
Mortar made from pure or "fat" lime cannot withstand the action of water, and is only used for work done above water-level.
In fact, ordinary pozzuolanic cement made on the spot where it is to be used may be regarded as a better kind of common mortar having hydraulic qualities.
When gauged with water and made into a mortar it sets slowly, but ultimately becomes almost as strong as Portland cement.
It is also employed for the building of light bridges, floors, and pipes constructed of cement mortar disposed round a skeleton of iron rods.
But where the concrete or mortar is not well made and is porous, the continual passage of water through it will gradually break up and dissolve away the calcareous constituents of the cement until its strength is utterly destroyed.