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NAK

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NAILS (from the Saxon ncegl) in building, &c., small metal-line-spikes, serving to bind or fasten the parts together, &c.

The several kinds of nails are very numerous ; as back-nails, made with flat shanks to hold fast, and not open thewood. Clamp-nails, proper to fasten the chimps in build-ings, &c. Clasp-nails, or brads, whose heads being flatted,

clasp and stick into the wood, rendering the work smooth,so as to admit a plane over it : the most common in buildingare distinguished by the names ten-penny, twenty-penny,two-shiUing, &c. Clench-nails, used by boat, barge, 8cc.,builders, with boves or nuts, and often without: for finework, they are made with clasp heads, or with the head beatflat on two sides. Clout-nails, ordinarily used for nailing onof clouts to axle-trees, are flat-headed, and iron-work isusually fixed with them. Deck-nails are for fastening ofdecks in ships, doubling of shipping, and floors laid withplanks. Dog-nails, or jobent-nails, proper for fastening ofhinges to doors, &c. Flat-points are of two kinds, viz. long,much used in shipping, and proper where there is occasionto draw and hold fast, yet no necessity of clenching ; andshort, which are fortified with points, to drive into oak, orother hard wood. Dead-nails used to nail lead, leather, andcanvass, to hard wood, are the same as clout-nails, dipped inlead or solder. Port-nails, commonly used for nailing hingesto the ports of ships. Ribbing-nails, used to fasten the rib-bing, to keep the ribs of ships in their place in building.Rose-nails are drawn square in the shank, and commonly ina round tool. Rother-nails, chiefly used to fasten rother-irons to ships. Scupper-nails, much used to fasten leatherand canvass to wood. Sharp-nails, much used, especiallyin the West Indies , with sharp points and flat shanks.Sheathing-nails, used to fasten sheathing-boards to ships :the rule for their length is, to have them full three times aslong as the board is thick. Square-nails, of the, same shapeas sharp-nails; chiefly used for hard wood. Brads, longand slender, without heads, used for thin deal work, to pre-vent splitting. To these may be added tacks; the smallest"serving to fasten paper to wood ; middling, for wool-cardsand oars ; and larger, for upholsterers and pumps. Theyare distinguished by the names of white-tacks, two-penny,three-penny, and four-penny, tacks.

NAIL-HEAD MOULDING, a Norman moulding, sonamed from its appearance, which is that of a surface studdedwith nails or nail-heads.

NAKED F'LOOEING, the whole assemblage, or contig-nation of timber-work, for supporting the boarding of a flooron which to walk. Naked flooring consists of a row ofparallel joists, called floor-joists.

When naked flooring consists of two rows of joists, ofwhich the upper is supported by the under row, all thejoists of the upper row crossing every one of the under atright angles, the supporting or lower row are called binding-joists ; while the joi.-ts supported, or those of the upper row,are denominated bridging-joists. When the ends of binding-joists are framed into each side of a str.ong beam, such beamis called a girder. There are many curious methods of join-ing timbers in short lengths ; for which the reader whosecuriosity inclines to investigations of this nature, may con-sult the subsequent part of this article, from Wallis’s OperaMalhematica, vol. I. prop. x. chap, vi., where he will findthe demonstrations relating to the strength of limbers,

and w

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according to their dispositions and bearings, a” u ; ( |,eseveral very ingenious methods of combining timbersforms of squares, oblongs, equilateral triangles, and P® c j e ggons, are shown by that renowned author. Of thissp 6 jof flooring, Serlio has exhibited a design. Godfrey KicjJin liis Palladio, exhibits the diagrams of two floors of jdescription, executed in Somerset House, which, he ■ j t y j“ was a novelty in England.” Notwithstanding the ' n » e . n uS p, !of this method of construction, it has been long out o f jprobablv, from the general introduction of foreign tin 1 j jwhich furnishes any lengths requisite for the purp° s j

building.

All the joists in the same floor, to which the board*^^,attached, should be disposed in one direction, as the hea g fjoints of one set of boards should never meet the edg ' fanother : the strength of the work, however, is by no j,ito be sacrificed, by a wrong disposition of the joist in .-| )( ,| )order to make the joints of the boarding parallel to jother ; symmetry of appearance being but a trifle con .' ull ,ikto the strength of the work. Indeed, the ends of the 1 „

may be made to meet the edges of others under the .^iedge of the door in each apartment, should such a disp°be necessary. _ . r uH

In double naked flooring, when the binding-J 013 ' _. t to

parallel to the chimney side of the room, the joist ^

such side ought to be placed at a distance from the L re ‘

_t •_ _i xi.„ i_.in. .1* it., i._ii. mi ti i

the chimney, equal to the breadth of the hearth, with iin ^ r(t ,J,

ance for the brick trimmer by which the hearth is supp

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Floors are constructed by different methods, acco 1

the bearing of the timber. When the rooms

have

o . . | • -.fa * v

dimensions, the floor generally consists of single jois 13 t yr

large, the framing for the support of the floor consist 3 ^ d' 6

rows of beams, the lower supporting the higher : v * ^ to 0exfent is so great, that the lower rows of beams won j',if

much weakened to support the upper rows and the , oC eii,, . . , n j • -i — intro"

walking upon, a strong beam, called a girder, is i |ltlu

so as to divide the length of the apartment ; or (vV< t > j J1 .ee&e., are introduced, so as to divide the length into ue 1 *

tlx*

four equal parts, as may be required for bearing tl |e ( ji _The girders thus introduced should always be place* q|iijbreadth or least dimension of the rectangle, or n 1 ’ 1

lower row of parallel beams are called binding'J° lthe transverse beams, which are supported by the 111 ’ j it) 111ings, or bridging-joists. The binding-joists are f ri ' n ' ,i tl ,e

the girder, or girders, and the bridgings are notched ^

binding-joists. . ^.jtlw

Plate 1. Figure 1.—A section of naked floom 1 ?’.^binding-joists, but with a girder, into which the J" 1 .^ i' ,asupport the flooring are framed, and the ceilb'r'J 1 ’^ d 1

deep joists, which also support the boarding. 1 l‘ e ce^"' r t i" ‘ ■ ' ns of t“e v ife

the of 'JIJ

the sections of the boarding-joists, as also the sect'°^ t/strong joists, and the sides or longitudinal direc

ceiling-joists. sh°" ,S ,!ir

Figure 2.—A section of a double floor. -C' 10 ; f tl' 15 ^ •},longitudinal section of the binding-joists, a section jits itier, and the sections of the bridging and ceilingshows the sections of the binding-joists, and the 0directions of the bridging and ceiling-joists. _ long*' 1 ’ ^When girders are extended beyond a certain

girder is shown in No. 1, as also the sectionsjoist?. No. 2, is the transverse section of