In all questions of packing long objects, it must be remembered that the best points of support for equality of strains are at 21 per cent (say ⅕) from each end. Any long stone must therefore be held in its case by cross bars or thicker pads or hay at ⅕ from each end. It is impossible to reckon on a case being so rigid, and so perfectly fitting, that it will give uniform support all along, with a much smaller elasticity than that of the stone. The utmost any case can do for stone is to deaden blows and shocks, and to hold the stone so that it is equally likely to break in the middle or at the supports; and this is gained by the grip at ⅕ from each end. A good packing for small slabs that are not liable to break, is a shallow box ([Fig. 50]), with the stone face down on dried fodder or straw, and two cross bars parallel and diagonal on the top, to hold the stone in. Such a box is easily lifted by the bars, saves all Customs examination, and will not tempt thieves. In all instances remember that it is useless to put general softening round stones in a box. The best points to take the pressure should be considered, and then thick pads nailed on the box to catch those best points of contact.
Fig. 51.—Tray for carrying heavy blocks of stone, lashed on by ropes through the holes.
Heavy stones.
The largest stones cannot usefully have any case; as a case which would not be cracked up by the weight in moving, would be so thick and heavy that it would make the stone far less moveable. If the stone is strong it only needs three or four thicknesses of old clothes and sacking tightly roped on, in order to travel safely. If it has a tender face, a skin of board may be put over that with some cotton-wool padding under the sacking cover. It is best for blocks of 1 to 4 cwt. to make a tray ([Fig. 51]) with poles projecting a foot at each corner to serve as handles, and then lash the block firmly on the tray. This encourages porters to lift it rather than throw it over. Such things as granite columns or colossi need no cover, but only softening of wood or pads, put under bearing points during moving. On shipboard they travel best laid at the bottom of a cargo of beans in bulk or bales of cotton, which wedge them tight.
Pottery.
Pottery is the most troublesome stuff to pack. The difficulty lies in keeping the packing material at the right places, and preventing it lumping together and so letting the contacts become bare. All the larger hollows must be filled with small pottery, or very light boxes, or empty tins, so that the packing cannot shift together. For large jars it is best to roll up straw in cloth to form cushions 1 to 2 inches thick, and nail these on the box at the points of contact; always observing if the jar can get loose by skewing into the diagonal. It is often needful to tie cotton stuff over the mouths of jars to prevent the packing working loose into the jar. For flat open forms, such as dishes and wide bowls, a stack should be made with the flattest below, so that each dish rests solely on its centre, and all the edges are free. A very little softening between them, and a firm block (such as a round tin pot) in the top one to take the pressure, will make them all travel with a solid contact right through the centres, so that each brim only carries its own weight. Even thin glass dishes can be packed safely in stacks in this way.
Glazed pottery is sometimes very fragile and full of cracks. To save it from falling apart it should be wound with string crossing diagonally in every direction, as tightly as it can be pulled. This firmly binds the jar so that it cannot fall apart. A couple of inches of tightly rammed softening all round it, will make it then travel quite safely.
Softening.
The material for packing, or softening, varies with the country and the season. In England there is nothing so good as the fine shavings known as “wood-wool.” In Egypt the best stuff is helbeh, a dried green crop which is very clinging, and holds in any position in which it is thrust. Tibn, or chopped straw, is also useful for ramming tight in small spaces. Firm cushions on fixed bearing points are made by rolling up straw in old cloth, and nailing the edges on the box, so that the pressure can never reach the nails. Rough country cotton can be had, but it is dear; and two or three pounds of prepared cotton wool in sheets should be taken for packing delicate things. Plenty of whitey-brown kitchen paper should be taken for wrapping; and some cartridge paper or brown paper for parcels. Stocks of nested parcel-post boxes are very useful; but sliding lids fall out loose by contraction, and glued joints crack to pieces. The domestic stock of biscuit boxes and food tins of course all come in for varied use.