Popular Technology; or, Professions and Trades. Vol. 2 (of 2)
Part 8
29. _Gothic style._--The Goths, who overran a great part of the Western empire, were not the inventors of the style of architecture which bears their name. The term was first applied with the view to stigmatize the edifices of the middle ages, in the construction of which, the purity of the antique models had not been regarded. The term was at first very extensive in its application; but it is now confined chiefly to the style of building which was introduced into various parts of Europe six or eight centuries ago, and which was used in the construction of cathedrals, churches, abbeys, and similar edifices.
30. The Gothic style is peculiarly and strongly marked. Its principles seem to have originated in the imitation of groves and bowers, under which the Druid priests had been accustomed to perform their sacred rites. Its characteristics are, pointed arches, pinnacles and spires, large buttresses, clustered pillars, vaulted roofs, and a general predominance of the perpendicular over the horizontal.
31. The ecclesiastical edifices of this style of building are commonly in form of a cross, having a tower, lantern, or spire, erected at the point of intersection. The part of the cross situated towards the west is called the _nave_; the eastern part, the _choir_; and the transverse portion, the _transept_. A glance at the following diagram will enable the reader to understand the form of the ground-work more fully.
32. Any high building erected above a roof is called a _steeple_, which is also distinguished by different appellations, according to its form: if it is square topped, it is a _tower_; if long and acute, a _spire_; or if short and light, a _lantern_. Towers of great height in proportion to their diameter are denominated _turrets_. The walls of Gothic churches are supported on the outside by lateral projections, called _buttresses_, which extend from the bottom to the top, at the corners and between the windows. On the top of these are slender pyramidal structures or spires, called _pinnacles_. The summit or upper edge of a wall, if straight, is called a _parapet_; if indented, a _battlement_.
33. Gothic pillars or columns are usually clustered, appearing as if a number were bound together. They are confined chiefly to the inside of buildings, and are generally employed in sustaining the vaults which support the roof. The parts which are thrown out of a perpendicular to assist in forming these vaults, have received the appellation of _pendentives_. The Gothic style of building is more imposing than the Grecian; but architects of the present day find it difficult to accomplish what was achieved by the builders of the middle ages.
34. In the erection of edifices at the present day, the Grecian and Gothic styles are chiefly employed, to the exclusion of the others, especially in Europe and America. Modern dwelling-houses have necessarily a style of their own, so far as relates to stories, windows, and chimneys; and no more of the styles of former ages can be applied to them, than what relates to the unessential and decorative parts.
THE CARPENTER.
1. It is the business of the carpenter to cut out and frame large pieces of timber, and then to join them together, or fit them to brick or stone walls, to constitute them the outlines or skeleton of buildings or parts of buildings.
2. The joiner executes the more minute parts of the wood-work of edifices, comprehending, among other things, the floors, window-frames, sashes, doors, mantels, &c. Carpentry and joinery, however, are so nearly allied to each other, that they are commonly practised by the same individuals; and, in this article, they will be treated together.
3. Carpentry and joinery, as well as all other trades connected with building, are subservient to the architect, when an individual of this particular profession has been employed; but it most commonly happens, that the master-carpenter acts in this capacity. This is especially the case in the erection of common dwellings, and, in fact, of other edifices where nothing very splendid is to be attempted. It is to be regretted, however, that the professional architect has not been oftener employed; for, had this been the case, a purer taste in building would have generally prevailed.
4. Contracts for the erection of buildings are often made with the carpenter, as master-builder or architect. In such cases, it is his business to employ persons capable of executing every kind of work required on the proposed edifice, from the bricklayer and stone-mason to the painter and glazier. It not unfrequently happens, however, that the person himself, who proposes to erect a building, chooses to employ the workmen in the different branches.
5. The constituent parts of buildings having been explained in the article on architecture, it is unnecessary to enter here into minute details on this point; nor would a particular description of the various operations of the carpenter and joiner be useful to the general reader, since, in every place, means are at hand by which a general view of this business may be obtained by actual inspection.
6. The carpenter and joiner are guided, in the performance of their work, by well-defined rules, drawn chiefly from the science of Geometry, and which they have learned from imitation and practice, as well as, in many cases, from the valuable works which have been published on these branches of the art of building.
7. The principal tools with which they operate are the axe, the adze, the saw, the auger, the gauge, the square, the compasses, the hammer, the mallet, the crow, the rule, the level, the maul, and the plane; and of many of these there are several kinds.
8. The timbers most employed in building in the United States are chiefly pine, oak, beech, black walnut, cypress, larch, white cedar, and hemlock; but of these pine is in the greatest use. Oak and beech are much used in constructing frames, in which great strength is required. Of the pine, there are several species, of which the white and yellow are the most valuable; the former of these grows in the greatest abundance in the Northern, and the latter, in the Southern states.
9. Vast quantities of timber are annually cut into boards in saw-mills, and floated down the rivers from the interior, during the time of high water in the spring and fall, and sometimes at other seasons of the year. The boards, or, as they are frequently denominated, planks, are placed in the water, one tier above another, and fastened together with wooden pins. Several of such _rafts_ are connected by means of withes to form one; and, at each end of this, are placed one or two huge oars, with which it may be guided down the stream. Upon these rafts, shingles and laths are also brought to market.
10. Logs and scantling to be employed in the frames of buildings are also conveyed down the rivers in the same manner. The business connected with the production of shingles, laths, boards or planks, and staves, is called lumbering; and it is carried on, more or less extensively, in the regions near the sources of all the large rivers in the United States, and in the British possessions in North America.
11. The trade in lumber has also given rise to another class of men, called lumber merchants; these purchase the lumber from the original proprietors, who bring it down the rivers, and, in their turn, sell it to builders and others. The lumbering business employs a large capital, and a numerous class of our citizens.
THE STONE-MASON, THE BRICKMAKER, &c.
THE MASON.
1. The art of Masonry includes the sawing and cutting of stones into the various shapes required in the multiplied purposes of building, and in placing them in a proper manner in the walls and other parts of edifices. It is divided into two branches, one of which consists in bringing the stones to the desired form and polish, and the other, in laying them in mortar or cement.
2. The rocks most used in building in the United States, are marble, granite, greenstone, scienite, soap-stone, limestone, gypsum, and slate. These are found in a great many localities, not only on this continent, but on the other side of the Atlantic. Of these stones, there are many varieties, which are frequently designated by their sensible qualities, or by the name of the place or country whence they are obtained; as _variegated_, _Italian_, _Egyptian_, or _Stockbridge marble_, and _Quincy stone_.
3. _The Stone-cutter._--Stone-cutters procure their materials from the _quarry-men_, whose business it is to _get out_ the stones from the quarries, in which they lie in beds, consisting either of strata piled upon each other, or of solid masses. Stones of any desirable dimensions are detached from the great mass of rock, by first drilling holes at suitable points, and then driving into them wedges with a sledge. These blocks are usually removed from the quarries, and placed on vehicles of transportation, by means of huge cranes, with which is connected suitable machinery.
4. The blocks of stone, received in their rough state by the stone-cutter, are divided, if required, into pieces of smaller size, by means of a toothless saw, aided by the attrition of sand and water. The other rough sides of the blocks are reduced to the proper form by means of steel _points_ and _chisels_ driven with a mallet. A kind of hammer with a point or chisel-like edge, is also used to effect the same object, especially in the softer kinds of stone.
5. For some purposes, the stones are required to be polished. This is especially the case with those employed in the ornamental parts of buildings. In the execution of this part of the work, the surface is rubbed successively with sand, freestone, pumice-stone, Scotch stone, crocus, and putty. When the face is a plane, the sand is applied by means of another stone, which is moved backwards and forwards upon it. In this way, two surfaces are affected at the same time.
6. In polishing irregular surfaces, the different kinds of stone are used in masses of convenient size; and the part applied to the surface to be polished is first brought to a form corresponding to it. The putty is an oxyde of tin, in form of powder. Crocus is the peroxyde of iron. The building-stone capable of receiving the highest polish is marble; and it is on this material that the stone-cutter, and the architectural carver or sculptor, exert their utmost skill; but some of the other stones which have been mentioned, possess the same quality to a considerable extent.
7. Carving architectural ornaments, such as pillars with their capitals, is a refined branch of this business; or it may rather be considered, of itself, a branch of sculpture. In the execution of this kind of work, the operator is guided by patterns, formed from the well-defined rules of the science of building. Very few stone-cutters attempt the execution of work so very difficult.
8. From the manufacture of mantel-pieces and monuments for the dead, the stone-cutter derives a great proportion of his profits. This will be manifest even to the superficial observer who may visit a few of the many stone-cutters' yards, to be found in any of our large cities. In some of these, blocks of marble are cut into slabs by the aid of steam-power.
9. In districts of country, also, where valuable stone is abundant, water is extensively employed for the same purpose. This is especially the case in Berkshire county, Massachusetts, where marble of a good quality is abundant. A great proportion of the marble slabs used by the stone-cutter are obtained from such mills. Some other operations of this business are also sometimes performed by the aid of machinery.
THE STONE-MASON.
1. In Philadelphia, and in many other cities not only in this country, but also in Europe, the stone-cutters _set their own work_; and this practice has led to the habit of applying the term stone-mason to both stone-cutters and those who lay stone in mortar and cement. In New-York, however, as well as in some of the cities farther east, these two employments are kept more distinct. The stone-cutters in Philadelphia are sometimes denominated marble-masons.
2. But, in every city, there are persons called stone-masons, whose business consists exclusively in constructing the walls and some other parts of buildings with stone; and their operations are considerably enlarged in those places where there are no marble-masons. In many cases, the bricklayer is also so far a stone-mason, as to lay the foundation-walls of the buildings which he may erect. This is especially the case in the country, where the divisions of labor are not so minute as in cities. It may be well here to remark, also, that the bricklayers, in some places, perform the services of the marble-mason.
3. The marble-mason, in joining together several pieces in a monument, employs a kind of cement composed of about six parts of lime, one of pure sand, a little plaster, and as much water as may be necessary to form it to the proper consistency. No more of this cement is used than is required to hold the blocks or parts together, as one great object of the artist is to hide the joints as much as possible. The substance thus interposed, becomes as hard as the marble itself.
4. The cement employed in laying marble in common or large edifices, is somewhat different from that just described, as it consists of about three fourths of lime and one of sand. The latter substance is obtained, in an unmixed state, on the bays in every part of the world; hence it has received the appellation of _bay sand_.
5. When it cannot be conveniently had in a pure state, particles of the same kind can be separated in sufficient quantities from their admixture with other substances. This is effected by sifting the compound through a sieve, into a small stream of water, which carries off the lighter particles that are unfit for use, whilst the sand, by its superior specific gravity, sinks to the bottom. The part which may be too coarse, remains in the sieve. This, however, except the rubbish, can be used in the coarser kinds of masonry.
6. The mortar, used in laying bricks and common stone, has a greater proportion of sand, which is generally of an inferior quality. Besides, the materials are incorporated with less care. Lime for the purposes of building is procured chiefly by calcining limestone in a kiln, with wood, coal, or some other combustible substance. It is also obtained by burning chalk, marble, and marine shells. Water poured upon newly-burnt or _quick_ lime, causes it to swell, and fall to pieces into a fine powder. In this state it is said to be _slacked_.
7. Masonry is often required in situations under water, especially in the construction of bridges and locks of canals. Common mortar resists the action of the water very well, when it has become perfectly dry; yet, if it is immersed before it has had time to harden, it dissolves, and crumbles away.
8. The ancient Romans, who practised building in the water to a great extent, discovered a material, which, when incorporated with lime, either with or without sand, possessed the property of hardening in a few minutes even under water. This was a kind of earth found at Puteoli, to which was given the name of _pulvis puteolanus_, and which is the same now called _puzzolana_.
9. A substance denominated _tarras_, _terras_, or _tras_, found near Andernach, in the vicinity of the Rhine, possesses the same quality with puzzolana. It is this material which has been principally employed by the Dutch, whose aquatic structures are superior to those of any other nation in Europe. Various other substances, such as baked clay and calcined greenstone, reduced to powder, afford a tolerable material for water-cements. Several quarries of water lime, which is similar in appearance to common limestone, has been lately discovered in the United States, which, being finely pulverized and mixed with sand, makes very good water-cement.
10. In buildings constructed with marble and other costly stones, the walls are not composed of these materials in their entire thickness; but, for the sake of cheapness, they are formed on the inside with bricks, commonly of a poor quality, so that in reality they can be considered only brick walls faced with stone. These two kinds of materials have no other connexion than what is produced by the mortar which may have been interposed, and the occasional use of clamps of iron. Such walls are said to be liable to become convex outwardly from the difference in the shrinking of the cement employed in laying the two walls.
11. The principal tools employed in cutting and laying stone are the saw, various kinds of steel points, chisels and hammers, the mallet, the square, the compasses, the level, the plumb-rule, the trowel, and the hod, to which may be added, the spade and the hoe. The last three instruments, however, are handled almost exclusively by laborers.
12. Besides these, contrivances are required to raise heavy materials to the various positions which they are to occupy. These consist, for the most part, of one or two shafts, commonly the mast of an old vessel, to which are attached tackle extending in various directions, and also those by which the blocks are to be raised. The rope belonging to the hoisting tackle is pulled by a machine worked with a crank.
13. Masonry is one of the primitive arts, and was carried to great perfection in ancient times. The pyramids of Egypt are supposed to have stood about three thousand years, and they will probably remain for centuries to come, monuments as well of the folly as of the power and industry of man. The temples and other magnificent structures of Greece and Rome, exhibit wonderful skill in masonry, and leave but little, if anything new, to be achieved in modern times.
THE BRICKMAKER.
1. Brick is a sort of artificial stone, made principally of argillaceous earths formed in moulds, dried in the sun, and burned with fire.
2. The earliest historical notice of bricks is found in the book of Genesis, where it is stated that the posterity of Noah undertook to build a city and a lofty tower of this material. Whether the bricks were really exposed to the action of fire, as the passage referred to seems to imply, or only dried in the sun, is an unsettled point. But Herodotus, who visited the spot many centuries afterwards, states that the bricks in the tower of Babylon were baked in furnaces.
3. It is evident, however, that the earliest bricks were commonly hardened in the sun; and, to give them the requisite degree of tenacity, chopped straw was mixed with the clay. The manufacture of such bricks was one of the tasks imposed upon the Israelites, during their servitude with the Egyptians.
4. The extreme dryness and heat of the climate in some of the eastern countries, rendered the application of fire dispensable; and there are structures of unburnt bricks still remaining, which were built two or three thousand years ago. Bricks both sun-dried and burned, were used by the Greeks and the Romans.
5. The walls of Babylon, some of the ancient structures of Egypt and Persia, the walls of Athens, the rotunda of the Pantheon, the temple of Peace, and the Thermæ, or baths, at Rome, were all built of brick. The most common bricks among the Romans were seventeen inches long and eleven broad; a size, certainly, far preferable, as regards appearance, to those of modern manufacture.
6. In the United States, a great proportion of the edifices, particularly in the cities and towns, are constructed of bricks, which are usually manufactured in the vicinity of the place where they are to be used. The common clay, of which they are made, consists of a mixture of argillaceous earth and sand, with a little oxyde of iron, which causes them to turn red in burning. The material for bricks is dug up, and thrown into a large heap, late in the fall or in the winter, and exposed to the influence of the frost until spring.
7. The operation of making bricks is conducted very systematically; and, although every part of the work seems to be very simple, it requires considerable dexterity to perform it properly and to the best advantage. The workmen, in the yards about Philadelphia, are divided into _gangs_ consisting of three men and a boy. The first is called the _temperer_, who tempers the material with water and mixes it with a spade; the second is called the _wheeler_, who conveys it on a barrow to a table, where it is formed in moulds by the _moulder_, whence it is carried to the _floor_ by the boy, who is denominated the _off-bearer_.
8. The bricks are suffered to remain on the floor a day or two, or until they have become dry enough to be handled with safety. They are then removed and piled into a _hack_, under cover, in such a manner that the air may circulate freely between them. It is the business of the whole gang to remove the bricks from the floor, and also to place them in the kiln to be burned. In both cases, each one has his due proportion of labor to perform.
9. The day's work of a gang, when the weather is favorable, is to make and pile in the hack a tale of bricks, which consists of 2332, or an even 2000. The former number is called a _long tale_, and the latter, a _short tale_. Considerable skill and much care are required in burning the bricks in a proper manner; too much fire would cause them to vitrify, and too little would leave them soft, and unfit for atmospheric exposure.
10. In many places, the clay is mixed or prepared for the moulder by driving round upon it a yoke of oxen, or by means of a simple machine, consisting of a beam, into which has been driven a great number of spokes. One end of this beam is confined in a central position, while the other is moved round in a sweep by animal power.
11. Machines have also been invented by the aid of which the clay may be both mixed and moulded; but these have been very little used. A machine, however, is often employed in pressing bricks which have been formed in the usual manner. The pressing is done after the bricks have become partially dry. Such bricks are employed in facing the walls of the better kinds of structures.
12. _Tiles._--Tiles are plates used for covering roofs. They resemble bricks in their composition and mode of manufacture, and are shaped in such a manner that when placed upon a building, the edge of one tile receives that next to it, so that water cannot percolate between them. Tiles, both of burnt clay and marble, were used by the ancients; and the former continue to be employed in various parts of Europe. Flat tiles are used for floors in many countries, and especially in Italy.
THE BRICKLAYER.
1. The particular business of the bricklayer is to lay bricks in mortar or some other cement, so as to form one solid body; but he frequently constructs the foundations of buildings in rough stones, and, in some cities, he sets hewn stone in the superstructure. In the country, plastering is likewise connected with this business.
2. Bricklaying consists in placing one brick upon another in mortar, chiefly in the construction of walls, chimneys, and ovens. In connecting these materials, especially in walls, two methods are employed, one of which is called the _English bond_, and the other, the _Flemish bond_. In the former method, the bricks are most commonly of one quality, and are laid crosswise and lengthwise in alternate rows. The bricks which are laid across the wall are called _headers_, and those which are laid in the other direction are called _stretchers_. The brick-work of the Romans was of this kind, and so are the partition-walls of many modern brick edifices.