Part 10

CARPENTER, WILLIAM BENJAMIN (1813-1885), English physiologist and naturalist, was born at Exeter on the 29th of October 1813. He was the eldest son of Dr Lant Carpenter. He attended medical classes at University College, London, and then went to Edinburgh, where he took the degree of M.D. in 1839. The subject of his graduation thesis, "The Physiological Inferences to be Deduced from the Structure of the Nervous System of Invertebrated Animals," indicates a line of research which had fruition in his _Principles of General and Comparative Physiology_. His work in comparative neurology was recognized in 1844 by his election to the Royal Society, which awarded him a Royal medal in 1861; and his appointment as Fullerian professor of physiology in the Royal Institution in 1845 enabled him to exhibit his powers as a teacher and lecturer, his gift of ready speech and luminous interpretation placing him in the front rank of exponents, at a time when the popularization of science was in its infancy. His manifold labours as investigator, author, editor, demonstrator and lecturer knew no cessation through life; but in assessing the value of his work, prominence should be given to his researches in marine zoology, notably in the lower organisms, as Foraminifera and Crinoids. These researches gave an impetus to deep-sea exploration, an outcome of which was in 1868 the "Lightning," and later the more famous "Challenger," expedition. He took a keen and laborious interest in the evidence adduced by Canadian geologists as to the organic nature of the so-called _Eozoon Canadense_, discovered in the Laurentian strata, and at the time of his death had nearly finished a monograph on the subject, defending the now discredited theory of its animal origin. He was an adept in the use of the microscope, and his popular treatise on _The Microscope and its Revelations_ (1856) has stimulated a host of observers to the use of the "added sense" with which it has endowed man. In 1856 Carpenter became registrar of the university of London, and held the office for twenty-three years; on his resignation in 1879 he was made a C.B. in recognition of his services to education generally. Biologist as he was, Carpenter nevertheless made reservations as to the extension of the doctrine of evolution to man's intellectual and spiritual nature. In his _Principles of Mental Physiology_ he asserted both the freedom of the will and the existence of the "Ego," and one of his last public engagements was the reading of a paper in support of miracles. He died in London, from injuries occasioned by the accidental upsetting of a spirit-lamp, on the 19th of November 1885.

CARPENTRAS, a town of south-eastern France, capital of an arrondissement in the department of Vaucluse 16 m. N.E. of Avignon by rail. Pop. (1906) town, 7775; commune, 10,721. The town stands on the left bank of the Auzon on an eminence, the summit of which is occupied by the church of St Siffrein, formerly a cathedral, and the adjoining law-court. St Siffrein, in its existing state, dates from the 15th and 16th centuries and is Gothic in style, but it preserves remains of a previous church of Romanesque architecture. The rich sculpture of the southern portal and the relics and works of art in the interior are of some interest. The law-court, built in 1640 as the bishop's palace, contains in its courtyard a small but well-preserved triumphal arch of the Gallo-Roman period. Other important buildings are the hospital, an imposing structure of the 18th century, opposite which is a statue of its founder, Malachie d'Inguimbert, bishop of Carpentras; and the former palace of the papal legate, which dates from 1640. Of the old fortifications the only survival is the Porte d'Orange, a gateway surmounted by a fine machicolated tower. Their site is now occupied by wide boulevards shaded by plane-trees. Water is brought to the town by an aqueduct of forty-eight arches, completed in 1734.

Carpentras is the seat of a sub-prefect and of a court of assizes, and has a tribunal of first instance, communal college for girls and boys, a large library and a museum. Felt hats, confectionery, preserved fruits and nails are its industrial products, and there are silk-works, tanneries and dye-works. There is trade in silk, wool, fruit, oil, &c. The irrigation-canal named after the town flows to the east of it (see VAUCLUSE).

Carpentras is identified with _Carpentoracte_, a town of Gallia Narbonensis mentioned by Pliny, which appears to have been of some importance during the Roman period. Its medieval history is full of vicissitudes; it was captured and plundered by Vandal, Lombard and Saracen. In later times, as capital of the Comtat Venaissin, it was frequently the residence of the popes of Avignon, to whom that province belonged from 1228 till the Revolution. Carpentras was the seat of a bishopric from the 5th century till 1805.

CARPENTRY, the art and work of a carpenter (from Lat. _carpentum_, a carriage), a workman in wood, especially for building purposes. The labour of the sawyer is applied to the division of large pieces of timber or logs into forms and sizes to suit the purposes of the carpenter and joiner. His working-place is called a sawpit, and his most important tool is a pit-saw. A cross-cut saw, axes, dogs, files, compasses, lines, lampblack, blacklead, chalk and a rule may also be regarded as necessary to him. But this method of sawing timber is now only used in remote country places, and in modern practice logs, &c., are converted into planks and small pieces at saw-mills, which are equipped with modern machinery to drive all kinds of circular saws by electricity, steam or gas.

Carpentry or carpenters' work has been divided into three principal branches--descriptive, constructive and mechanical. The first shows the lines or method for forming every species of work by the rules of geometry; the second comprises the practice of reducing the timber into

## particular forms, and joining the forms so produced in such a way as to

make a complete whole according to the intention or design; and the third displays the relative strength of the timbers and the strains to which they are subjected by their disposition. Here we have merely to describe the practical details of the carpenter's work in the operations of building. He is distinguished from the joiner by his operations being directed to the mere carcass of a building, to things which have reference to structure only. Almost everything the carpenter does to a building is absolutely necessary to its stability and efficiency, whereas the joiner does not begin his operations until the carcass is complete, and every article of joiners' work might at any time be removed from a building without undermining it or affecting its most important qualities. Certainly in the practice of building a few things do occur regarding which it is difficult to determine to whose immediate province they belong, but the distinction is sufficiently broad for general purposes.

The carpenter frames or combines separate pieces of timber by scarfing, notching, cogging, tenoning, pinning and wedging, &c. The tools he uses are the rule, axe, adze, saws, mallet, hammers, chisels, gouges, augers, pincers, set squares, bevel, compasses, gauges, level, plumb rule, jack, trying and smoothing planes, rebate and moulding planes, and gimlets and wedges. The carpenter has little labour to put on to the stuff; his chief work consists in fixing and cutting the ends of timbers, the labour in preparing the timber being done by machinery.

[Illustration: FIG. 1.--Lapped Joint.]

[Illustration: FIG. 2.--Fished Joint.]

[Illustration: FIGS. 3, 4 and 5.--Scarf Joints.]

_Joints._--The joints in carpentry are various, and each is designed according to the thrust or strain put upon it. Those principally used are the following: lap, fished, scarf, notching, cogging, dovetailing, housing, halving, mortice and tenon, stub tenon, dovetailed tenon, tusk tenon, joggle, bridle, foxtail wedging, mitre, birdsmouth, built-up, dowel. Illustrations are given of the most useful joints in general use, and these, together with the descriptions, will enable a good idea to be formed of their respective merits and methods of application.

The lapped joint (fig. 1) is used for temporary structures in lengthening timbers and is secured with iron straps and bolts; a very common use of the lap joint is seen in scaffolding secured with cords and wedges.

The fished joint (fig. 2) is used for lengthening beams and is constructed by butting the ends of two pieces of timber together with an iron plate on top and bottom, and bolting through the timber; these iron connecting-plates are usually about 3 ft. long and 1/4 in. and 1/2 in. in thickness. This joint provides a good and cheap method of accomplishing its purpose.

The scarf joint (figs. 3, 4 and 5) is used for lengthening beams, and is made by cutting and notching the ends of timbers and lapping and fitting and bolting through. This method cuts into the timber, but is very strong and neat; in addition for extra strong work an iron fish-plate is used as in the fished joint.

[Illustration: FIG. 6.--Notching.]

[Illustration: FIG. 7.--Cogging.]

The ends of floor joints and rafters are usually _notched_ (fig. 6) over plates to obtain a good bearing and bring them to the required levels. Where one timber crosses another as in purlins, rafters, wood floor girders, plates, &c, both timbers are notched so as to fit over each other; this _cogging_ (fig. 7) serves instead of fastenings. The timbers are held together with a spike. In this way they are not weakened, and the joint is a very good one for keeping them in position.

[Illustration: FIG. 8.--Dovetail.]

[Illustration: FIG. 9.--Housing.]

[Illustration: FIG. 10.--Halving.]

Dovetailing (fig. 8) is used for connecting angles of timber together, such as lantern curbs or linings, and is the strongest form. When an end of timber is let entirely into another timber it is said to be _housed_ (fig. 9). Where timbers cross one another and require to be flush on one or both faces, sinkings are cut in each so as to fit over each other (_halving_); these can either be square (fig. 10), bevelled (fig. 11) or dovetailed sinkings (fig. 12). The end of one piece of timber cut so as to leave a third of the thickness forms a _tenon_, and the piece of timber which is to be joined to it has a mortice or slot cut through it to receive the tenon; the two are then wedged or pinned with wood pins (fig. 13).

[Illustration: FIG. 11.--Bevelled Halving.]

[Illustration: FIG. 12.--Dovetailed Halving.]

[Illustration: FIG. 13.--Mortice and Tenon.]

[Illustration: FIG. 14.--Stub Tenon or Joggle.]

[Illustration: FIG. 15.--Dovetailed Tenon.]

[Illustration: FIG. 16.--Tusk Tenon.]

[Illustration: FIG. 17.---Bridle Joint.]

[Illustration: FIG. 18.--Foxtail Wedging.]

[Illustration: FIG. 19.--Dowelling.]

A stub tenon or joggle (fig. 14) is used for fixing a post to a sill; a sinking is cut in the sill and a tenon is cut on the foot of the post to fit into the sinking to keep the post from sliding.

The purpose of a dovetailed tenon (fig. 15) is to hold two pieces of wood together with mortice and tenon so that it can be taken apart when necessary. The tenon is cut dovetail shape, and a long mortice permits the wide part of the tenon to go through, and it is secured with wood wedges. Where the floor joists or rafters are trimmed round fires, wells, &c., the tusk tenon joint (fig. 16) is used for securing the trimmer joist. It is formed by cutting a tenon on the trimmer joist and passing it through the side of the trimming joist and fixing it with a wood key. Where large timbers are tusk tenoned together, the tenons do not pass right through, but are cut in about 4 in. and spiked.

A bridle joint or birdsmouth (fig. 17) is formed by cutting one end of timber either V shape or segmental, and morticing the centre of this shaped end. Similar sinkings are cut on the adjoining timber to fit one into the other; these are secured with pins and also various other forms of fastenings. Foxtail wedging (fig. 18) is a method very similar to mortice and tenon. But the tenon does not go through the full thickness of the timber; and also on the end of the tenon are inserted two wedges, so that when the tenon is driven home the wedges split it and wedge tightly into the mortice. This joint is used mostly in joinery. The mitre is a universal joint, used for connecting angles of timber as in the case of picture frames. Built-up joints involve a system of lapping and bolting and fishing, as in the case of temporary structures, for large spans of centering for arches, and for derrick cranes. Dowels are usually 3 or 4 in. long and driven into a circular hole in the foot of a door frame or post; the other end is let into a hole in the sill (fig. 19).

[Illustration: FIG. 20.--Method of supporting Centering for Concrete.]

_Centering._--Centering is temporary timber or framing erected so as to carry concrete floors or arches of brick or stone, &c.; when the work has set the centering is removed gradually. The centering for concrete floors is usually composed of scaffold boards resting on wood bearers (fig 20). One wood bearer rests along on top of the steel joists; through this bearer long bolts are suspended, and to the bottom of these bolts a second bearer is fixed, and on the bottom bearer the scaffold boards rest. Another method, not much used now, is to fit the boards to the size of the floor and prop them up on legs, but among other disadvantages this process takes up much space and is more costly.

[Illustration: FIG. 21.]

Turning piece is a name given to centering required for turning an arch over (fig. 21); it is only 4-1/2 in. wide on the soffit or bed, and is generally cut out of a piece of 3 or 4 in. stuff, the top edge being made circular to the shape of the arch. It is kept in position whilst the arch is setting with struts from ground or sills and is nailed to the reveals, a couple of cross traces being wedged between. In the case of a semicircular or elliptical arch with 4-1/2 in. soffit this turning piece would be constructed of ribs cut out of 4 in. stuff with ties and braces. Or the ribs could be cut out of 1 in. stuff, in which case there must be one set of ribs outside and one inside secured with ties and braces; each set of ribs when formed of thin stuff is made of two thicknesses nailed together so as to lap the joints. For spans up to 15 ft. the thin ribs would be used, and for spans above 15 ft. ribs out of 4 in. stuff and upwards. For arches with 9 in. soffit and upwards, whether segmental or semicircular or elliptical, the centres are formed with the thin ribs and laggings up to 15 ft. span; above 15 ft. with 4 in. ribs and upwards (fig. 22). The lower member of centres is called the tie, and is fixed so as to tie the extremities together and to keep the centre from spreading. Where the span is great, these ties, instead of being fixed straight, are given a rise so as to allow for access or traffic underneath. Braces are necessary to support the ribs from buckling in, and must be strong enough and so arranged as to withstand all stresses. Laggings are small pieces or strips of wood nailed on the ribs to form the surface on which to build the arch, and are spaced 1 in. apart for ordinary arches; for gauged arches they are nailed close together and the joints planed off. When centres are required to be taken down, the wedges upon which the centre rests are first removed so as to allow the arch to take its bearing gradually. Centres for brick sewers and vault arching are formed in the same way as previously mentioned, with ribs and laggings, but the thickness of the timbers depends upon the weight to be carried.

[Illustration: FIG. 22.--Centering for Stone Arch.]

[Illustration: FIG. 23.--Single Floor.]

_Floors._--For ordinary residential purposes floors are chiefly constructed of timber. Up to about the year 1895 nearly every modern building was constructed with wood joists, but because of evidence adduced by fire brigade experts and the serious fires that have occurred fire-resisting floors have been introduced. These consist of steel girders and joists, filled in with concrete or various patented brick materials in accordance with such by-laws as those passed by the London County Council and other authorities. The majority of the floors of public buildings, factories, schools, and large residential flats are now constructed of fire-resisting materials. There are two descriptions of flooring, single and double.

[Illustration: FIG. 24.--Floor pugged to resist passage of sound.]

Single flooring.

Single flooring (fig. 23) consists of one row of wood joists resting on a wall or partition at each end without any intermediate support, and receiving the floor boards on the upper surface and the ceiling on the underside. Joists should never be less than 2 in. thick, or they are liable to split when the floor brads are driven in; the thickness varies from 2 to 4 in. and the depth from 5 to 11 in. (see _By-laws_, below), the distance between each joist is usually 12 in. in the clear, but greater strength is obtained in a floor by having deep joists and placing them closer together. These floors are made firm and prevented from buckling by the use of strutting as mentioned hereafter.

The efficiency of single flooring is materially affected by the necessity which constantly occurs in practice of trimming round fireplaces and flues, and round well holes such as lifts, staircases, &c. Trimming is a method of supporting the end of a joist by tenoning it into timber crossing it; the timber so tenoned is called the trimmer joist, and the timber morticed for the tenon of the trimmer is called the trimming joist, while the intermediate timbers tenoned into the trimmer are known as the trimmed joists. This system has to be resorted to when it is impossible to get a bearing on the wall.

[Illustration: FIG. 25.--Double Floor, with Steel Binders.]

A trimmer requires for the most part to be carried or supported at one or both ends by the trimming joists, and both the trimmer and the trimming joists are necessarily made stouter than if they had to bear no more than their own share of the stress. In the usual practice the trimmer and trimming joists are 1 in. thicker than the common joists, but there are special regulations and by-laws set out in the various districts and boroughs (see _By-laws_, below) to which attention must be given.

[Illustration: FIG. 26.]

[Illustration: FIG. 27.--Construction of a Medieval Floor.]

The principal objection to single flooring is that the sound passes through from floor to floor, so that, in some cases, conversation in one room can almost be understood in another. To stop the sound from passing through floors the remedy is to pug them (fig. 24). This consists in using rough boarding resting on fillets nailed to the sides of the joists about half-way up the depth of the joists, and then filling in on top of the boarding with slag wool usually 3 in. thick. Also to further prevent sound from passing through floors the flooring should be tongued and the ceiling should have a good thick floating coat, in poor work the stuff on ceilings is very stinted. In days gone by, ceiling joists were put at right angles to the floor joists, but this took up head room and was costly, and the arrangement is obsolete.

[Illustration: FIG. 28.--Herring-bone Strutting.]

[Illustration: FIG. 29.--Solid Strutting.]

Double flooring.

Double flooring (fig. 25) consists of single fir joists trimmed into steel girders; in earlier times a double floor consisted of fir joists called binding, bridging and ceiling joists, but these are very little used now and the single fir joists and steel girders have taken their place. Steel girders span from wall to wall, and on their flanges are bolted wood plates to receive the ends of the single joists which are notched over plates and run at right angles to the girders (fig. 26). The bearings of the joists on the wall also rest on wall plates, so as to get a level bed, and are sometimes notched over them. Wall plates, which are usually 4-1/2 in. X 3 in. and are bedded on walls in motar, take the ends of joists and distribute the weight along the wall. The plates bolted on the side of girders are of sizes to suit the width of the flanges.

The medieval floor (fig. 27) consisted of the framed floor with wood girders, binding, bridging and ceiling joists; and the underside of all the timbers was usually wrought, the girders and binders being boldly moulded and the other timbers either square or stop chamfered.

Flooring is strengthened by the use of strutting, either herring-bone (fig. 28) or solid (fig. 29). Herring-bone strutting consists of two pieces of timber, usually 2 in. X 2 in., fixed diagonally between each joist in continuous rows, the rows being about 6 ft. apart. Solid strutting consists of 1-1/4 in. boards, nearly the same depth as the joists and fitted tightly between the joists, and nailed in continuous rows 6 ft. apart. Where heavy weights are likely to be put on floors long bolts are passed through the centre of joists at the side of strutting; since this draws the strutting tightly together and does not produce any forcing stress on the walls, it is undoubtedly the best method.

Floors are usually constructed to carry the following loads (including weight of floor):--

Residences, 1-1/4 cwt. per foot super of floor space.

Public buildings, 1-1/2 cwt. per foot super of floor space.

Factories, 2-1/2 to 4 cwt. per foot super of floor space.

_Local By-laws._--With regard to floor joists in domestic buildings, the following are required in the Hornsey district, in the north of London. The size of every common bearing floor joist up to 3 ft. long in clear shall be 3 in. X 2-1/2 in.; from 3 ft. to 6 ft. in clear it shall be 4-1/2 in. X 3 in.; from 6 ft. to 8 ft., 6-1/2 in. X 2-1/2 in.; from 8 ft. to 12 ft., 7 in. X 2-1/2 in., and so on according to the clear span. The Hornsey by-laws with regard to trimmers are as follows:--A trimmer joist shall not receive more than six common joists, and the thickness of a trimming joist receiving a trimmer at not more than 3 ft. from one end and of every trimmer joist shall be 1/8th of an inch greater than the thickness for a common joist of the same bearing for every common joist carried by a trimmer. For example, if the common joists are 7 in. X 2-1/2 in. and the trimmer has six joists trimmed into same, the size of trimmer would have to be 7 in. X 3-1/4 in. The Hornsey council also requires that the floor boards shall not be less than 7/8ths of an inch thick.