Fig. 2.
First of all, take the two wooden blocks and cut them the shape shown in [Fig. 1]; the width at top is three inches, and at the bottom five inches. Divide the top and bottom lines into two equal parts, and draw a line from top to bottom through the points of division. On this line mark a point an inch and a half from the top, and with this point as centre bore a hole right through the wood, which hole is to be just large enough for the wooden rods to fit tightly into. Draw a line across the face of the block half way down (as in [Fig. 2]). Along this line, and from each end of it, mark inwards a distance equal to the diameter of the wooden rods, and do the same along the bottom line (as in [Fig. 2]). Join these points as in the figure; cut out the middle portion, leaving the projections three inches long and an inch and a quarter square. These projections must be rounded by taking off the corners with a sharp chisel or knife. Trim them down till they are the same size as the rods.
Now you will want your fifteen wooden rods. See that they are all the same thickness. Cut off the ends of each, to make them quite square, and making the rods exactly three feet six inches long. From your tin plate cut fourteen pieces, each piece to be six inches long, and wide enough to go round the rods and to lap about a quarter of an inch. The width can be found by rolling paper round the rod and letting it lap a quarter of an inch, and then cutting it off. Place this paper on the tin and mark the width. The tin can be cut with a large pair of scissors. Now roll each piece of tin round the rods so as to form fourteen tubes. These tubes will now require to be soldered. You can get your tinman to do this for you, or you can do it yourself. If so, the following is the way to do it.
First of all, get some muriatic acid and some clean zinc cuttings. Put the zinc into a bottle and pour over it the acid, and set it on one side for a time till it has quite done effervescing; then add a little more zinc, and if it begins again wait a little longer and add more. Do this till it does not effervesce on putting new zinc into it, when it is ready for use. You must get some solder from the plumber’s, and if you have not a soldering-bit he will perhaps lend you one; but you can buy the bits now in many shops where they are sold on a card with some solder. The cost is from one shilling upwards.
The first thing to do is to ‘tin the bit’ (or cover the face and point with solder). This is done as follows. Place the bit in the fire to get hot, but not red. Take a clean piece of tin-plate and put on it a few drops of the zinc solution, and put a small piece of solder into it. When the bit is hot enough take it out of the fire, and with a coarse file clean the face and edges of it, and place it on the solder in the zinc solution on the piece of tin. In a few seconds the solder will melt and flow all over the point of the bit. This must be done to the bit every time it gets red-hot, as in that case the solder is burnt off.
Now put the bit back into the fire and take one of the tin tubes and first clean the surfaces that lap together by scraping them with a penknife. Rub each surface with the zinc solution and lap them together, and tie the tube round with string, to keep the edges in their places. Take the bit out of the fire when it is hot enough, and place it on the end of the stick of solder, which will be melted and stick to the bit. Place the bit on the top of the lapping edges, and in a few seconds the solder will flow from the bit between the surfaces to be joined, and by drawing the bit from one end to the other it will draw after it the solder and make a strong joint. If the bit did not at first carry enough solder to make the whole joint, more can be added by applying the stick of solder to the bit while it is on the joint. Solder the fourteen tubes, and clean off the joints by scraping and filing the superfluous solder off and polishing up with a piece of glass-paper. Clean the joint inside well with a piece of oiled rag to destroy the zinc solution left inside.
Now fit a tube on one end of each of fourteen of the wooden rods. The tube must be pushed on to the wood so that it is half way, or leaving an empty space of three inches. The tube can be fixed to the wood by two or three tacks driven through the tin. The fifteenth rod has no tube to it.
This is all there is to be made for the frame. In putting it together take the rod without a tube and two others, and join them together like a fishing rod, place each end of this compound rod into the hole in one of the blocks of wood, fit together the other rods into sets of three. There will be four of them. At one end of each set will be an empty tube, these are to be fitted on the pegs on the blocks at the ends of the other rod. The frame will now be composed of two uprights, each made up of two compound rods, and these support the cross rod or screen roller.
Fig. 3.