SHIP-BUILDING. 



rail and upper cheek, and the moulds made to them when 

 their fituation is determined on. 



But in order to fhew what may be performed on the floor, 

 the timbers of the head may not only be laid off, but the 

 bevellings taken, and the very fcores for the rails be cut out 

 thus : 



Take the heights in the flieer-plan, _/?§■. i, at the aft-fide 

 of each head-timber, from the upper fide of the upper 

 cheek to the upper and lower fides of each rail, for theout- 

 fide of the rail, and fet them up from the bafe line of their 

 correfponding timber, jig. 3, ftriking the horizontal lines as 

 there ticked. Then take the diftances from the middle 

 line in the half-breadth ^\zn. Jig. 2, at the aft-fide of each 

 timber to the out fide of each rail, and fet them off on their 

 correfponding ticked lines, _^. 3. Where the aft-fides of 

 the timbers, in the half-breadth plan,^^. 2, interfedt the 

 infide of the middle and lower rails, let them be drawn 

 fquare from the lines N and O, to interleft the lines of the 

 rails laid oft. Then take the diftances from the lines N and 

 O, on the lines fquared out, to the lines of the rails laid oft", 

 and fet them down from the lines ^3 and 34, at the aft-fides 

 of their refpeitive timbers in the ftieer-plan, ^^. i, making 

 fpots which form the upper fide of the rails at the infide, the 

 fame as was performed for the upper rail. Take the diftancf s 

 from the upper fide of the cheek in the ftieer-plan, Jig. 1, at 

 the aft-fide of tiie timbers, to the fpots laft mentioned, and 

 likewife to the line for the upper fide of the upper rail 

 at the infide, and fet them up from the bafe line of each re- 

 fpeftive timber in^^. 3, and ftrike a faint line. Then take 

 the diftances from the middle line in the half-breadth plan, 

 Jig. 2, at the aft-fide of each timber, to the infide of the 

 before-mentioned rails, and fet them off from the middle line 

 u, in the plan of the timbers,_^^. 3, on their correfponding 

 faint lines. This gives the upper part of the rails at the 

 infide. The fame operation may be performed to find the 

 lower part of the rails at the infide ; or you may draw the 

 infide of the rails perpendicular, and fet down the depth 

 of the rails agreeable to what they meafure on the moulds, 

 taken in the direftion of the timber. This may determine 

 the under fide of the rails at the infide. 



As the line of the chamfer of the upper rail N (being the 

 fight-fide of the rail when it is trimmed, and in its place) is 

 before reprefented in the fliecr-plan, _/ff . i, take the height 

 from the upper fide of the check to the chamfer of the rail, at 

 the aft fide of each timber, and fet it up from tlie bafe line of 

 each correfponding timber, jfg-. 3, ftriking faint lines parallel 

 to the bafe line. Then take the half-breadths at the aft-fide of 

 each timber in the half-breadth plan, fig. 2, to the ticked 

 line of the upper rail, (which is fiippofed to be where the 

 rail is alfo to be chamfered,) and let them off from the middle 

 line u, m Jig. 3, on their correfponding lines hit ftruck, 

 and from thence draw the under fide of the rail to tlie 

 infide. 



Having the upper fide of all the rails, infide and ontfide, 

 in the plan of the timbers, Jfg 3, fet oft', draw the line for 

 the upper fide of the rails, which ftiews how much the infi<le 

 of the rails is higher than the outfide, if cut oft in the di- 

 reftion of the aft-fide of the timber. Then having the 

 fpots, as before mentioned, for the outfide of the rails, 

 (being on the ticked lines firll drawn,) the under fide of the 

 rails may be drawn parallel to the upper, or to interfeft the 

 fpot before-mentioned for the infide, which was fet down 

 agreeable to what it meafureson the mould, taken in the di- 

 reftion of the rail, as it is marked on the mould. 



Having the fcores for the timbers, the half-thicknefs of 

 the knee of the head at the aft-fide of each timber, let 

 it oft" from the middle line a on the bafe line of it8 corre- 



VoL. XXXI r. 



fponding timber in fg. 3. Likewife take the height hom 

 the upper fide of the upper cheek in the ftieer-p!an, fig. i, 

 to the ticked curve, reprelenting the cutting, down or lacing 

 of the knee, and fet it up from the bafe line of each timber 

 '"A- 3- This will give the fcore to be cut out, in order 

 to let the timber meet its oppofite at the middle line. Then 

 fet oft" the fubftance at the upper fide of the upper cheek, 

 and draw the infide and outfide of the timber as reprefented 

 in the plate. This will be the exaft form of the timbers, 

 or more particularly, of the fcores of the middle rails ; and 

 if laid off in the grofs, might be performed to the greatelt 

 nicety. 



To bevel the Timbers in the Head. — In the ftieer-plan, Jig. i, 

 fet oft the fiding of the timbers, and ftrike in their fore-fides. 

 Then fquare a line from the aft-fide to the fore-fide, from 

 where the aft-fide interfefts the upper fide of the cheek, as 

 at 18, 19, 20, in the fame manner as was done to find the 

 bevellings of the cant-timbers. 



Take the heights at the fore-fide of each timber from its 

 heel, as fquared, to the upper and lower fides of the rails, in 

 the fame manner as direfted for the aft-fide, and fet them 

 up on the plan of each refpeftive timber, jig. 3 ; then fet 

 oft" the fore-fide of each timber in the half-breadth plan, 

 fg. 2, and take the diftances from the middle liite to the 

 outfide of each rail at the fore-fide of each timber, and fet 

 them oft' on the plan of each refpeftive timber, fig. 3, on 

 their correfponding horizontal lines laft mentioned." Where 

 the fore-fide of eacli timber in the half-breadth plan, /ff . 2, 

 interfefts the infide of the middle and lower railo, let them 

 be fquared out from the lines N and O, to interfeft the 

 lines of their correfponding rails laid off. Then take the 

 diftances from the lines N and O, in the half-breadth plan, 

 Jig. 2, agreeable to the lines fquared out, to the lines of the 

 rails laid off, and fet them down below their correfponding 

 lines 33, 34, Jig. i, at the fore-fide of each correfponding 

 timber in the ftieer-plan, _yff . i, making fpots. Then take 

 the heights from the fquare line at the heel up the fore-fide 

 of each timber in the ftieer-plan, /^. i, to the fpots laft 

 mentioned, and fet them up in the plan of their refpeftive 

 timbers, Jg. 3, ftriking new horizontal lines. Then take 

 the diftances from the middle line in the lialf-breadth plan, 

 fg. 2, at the fore-fide of each timber to the infide of the 

 rails, and fet them off on their correfponding liorizontal 

 lines laft ftruck, in the plan of each refpeftive timber,_^^. 3. 

 This will give the direftion of the upper fide of the rails, 

 and, if rightly perfurmed, will be parallel to tlie upper fide 

 of the rails laid oil' for the aft-fide. 



In the fame manner is every opcr.uioii performed for thf 

 fore-fide as was direfted for the aft-fide, the heights being 

 taken from the heel as fquared in the fheer-plan, ^^. i, in- 

 ftead of the ujjper fide of the cheek, which Ihews how much 

 the rails hft at the fore-fide from a fquare ; and the half- 

 breadths being taken at the fore-fide of the timbers in the 

 half-breadth plan, /ff. 2, ftiew liow much the fcores si the 

 fore-fide of the timbers are under from a fquaie with tlie aft- 

 fide, becaufe the timbers in the half-breadth plan are fquare 

 from the middle line. 



Having the dilpofition of the rails for the fore-fide of tlie 

 timbers, fet off the fame dillance from the rails as it is from 

 tlie rails of the aft-fide, both infide and outfide, and mark 

 the curves as ticked for the infide and outfide of each tim- 

 ber, in the plan of the timbers, _^i^. 3. Then whatever dif- 

 taiice the ticked lines of the fore-fide are from the lines of 

 the aft-fide, fo much is the outfide of the timber under, and 

 the infide Handing from a fquare, agreeable to the fiding of 

 the timber. Or, having the att-fides of the timbers laid off 

 exaftly, the fore and aft bevellings might be taken more cor- 



4 E reft 



