PLATE XI. DETAILS OF CONSTRUCTION.

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Fig.1 is an enlarged plan of Fig.1, PlateX. The face of risers must be set off on the centre line of rail to suit the falling line of handrail, which should be ascertained first. The line of travel is 15 inches from the centre line of rail, and the winders are divided on this line.

Fig.2 shows the development. Cut a piece of thin board to fit the face of string around the zinc circle on plan, as shown by Fig.3. Bend a thin lath around it, and mark the springing on to it and all risers between. Lay this lath on Fig.2, and mark the springing and position of risers, as shown. The position of risers outside of the springing can of course be taken off the plan. Draw one or two full size steps top and bottom, and a part of the straight strings as shown. Continue the bottom edge of string to form a nice easy falling line connecting the straight parts, as shown by the curved parts, Fig.2.

Fig.4 shows a cylinder made to fit the inside face of the circular string. Before the veneer is put on, glue some paper all over the outside of this cylinder and let it dry. Then, should any glue get between the veneer and cylinder, it will pull the paper off instead of sticking to the wood, and perhaps break the veneer; the paper can be washed off. Bend the lath around the cylinder on top of the paper, and mark the springing, as shown, on both sides. Do this at both ends, and mark the springing down the sides with a straight-edge. Now get a piece of veneer a full 1/16 inch thick, the size shown by the straight dotted lines, Fig.2. Cut the bottom edge to the curve SS. Mark the springing and each step on the veneer. It is as well to mark these on both sides. In putting this on the cylinder take care to have it the right hand. Fix on one side first with a hand-screw, so that the springing on the veneer is on the springing on the cylinder, then bend it around and fasten the other side temporarily. Then get two pieces of veneer, ? inch thick and about 1 inch wide, cut to the shape of the curves SS and NN. Now bend the two pieces around on the top of the first piece, keeping the edge SS flush with the bottom edge of the large veneer. It will be seen that the three thicknesses of veneer will form the sinking in the string 5/16 inch deep. Next get a piece the exact thickness of the sinking 5/16 inch, and cut it to the shape of the sinking, as seen at Fig.5. Put plenty of saw kerfs in the direction shown, that is, parallel to the springing. Let the kerfs go past the springing a bit on both ends. Now bend this around the cylinder with the kerfs next to it, and the edge close up to the veneers. Now get the staves about 2 inches by 2 inches, and bevel the edges to fit each other around the circle and hollow the under side to fit in the veneer, also cut the ends out to fit over the sinking. Start one side first with straight pieces as far as the springing and screw it down, then work from this piece and go right around, screwing each piece as it is fitted, until they are all on. Next start in the centre and take off one side, numbering each piece as it is taken off, lift up each of the three pieces of veneer and glue between them, screw the staves on again except the centre one, take them off on the other side and glue in the same way, after which screw on all the staves again. To glue the staves, again start in the centre and take off one, well glue the bottom next to the veneer and screw it down tight. Take off the next one to it and glue the bottom and side going against the one already glued. Repeat this process until all are fixed, but never glue more than one at a time. It may be found necessary to steam the veneer. This is sometimes done in a box made for the purpose, where there is steam to be had, but failing that, boiling in the glue-pot is used. But this is not a good thing to do if it can be avoided, as the dryer it is put on the better for the job. Fig.6 shows an enlarged section through the joint AB, Fig.4. F is a section of Fig.5.

Fig.7 shows the well in position. If a ?-inch bead is used for the bottom edge, a piece of ?-inch cane can be bent around the well in continuation of the bead. This work must be all fitted before it leaves the bench, ready to go into its place when fixed.


                                                                                                                                                                                                                                                                                                           

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