We may then dismiss all adhesives but flour paste, and glue; the former can be used by itself, but glue by itself is not very satisfactory. Together they give the best result, for reasons already stated.

It is desirable to mix some mineral matter with the paste, and for this use we find, among other additions, the 5 following recommended: - Whiting litharge, white lead, kaolin, other clays, Paris white, zinc white, barytes white.

The use of the mineral matter is twofold. It makes the compressed parts of the mould more hard and stony than they would otherwise be, and less subject to blister or scale during drying or casting, and it makes the uncompressed parts of the flong more spongy and uniform in texture." At the same time it makes the whole mould more resistant to heat.

Of the above, the only very definitely objectionable substances are litharge and white lead, as, owing to the moisture and heat the lead poison is specially liable to be absorbed into the system of the workmen; and of the rest, whiting seems the best, its softness of texture, fineness, and the ease with which it is compressed, enabling it well to fulfil the double function as stated above. At any rate, not one of the above is superior to whiting; whiting, moreover, is cheap, and easy to get. -

We now come to the preparation of the paste. Into an iron pan put 6 lb. whiting and 20 lb. (2 gal.) water. It the whiting is allowed to remain in the water for 1-2 hours it will be found that the lumps have completely broken down, and the mixing will be easy, If, on the other hand, you try to mix whiting which has only just been put in the water, it works into clots and becomes unmanageable. The hands form the most convenient tools for mixing the whiting and water, as also for working in the next addition, 4 1/2 lb. wheat flour.

This being thoroughly incorporated, the pan is set for the mixture to boil, it being constantly stirred with a wooden stirrer, having a T-shaped head which can be kept in motion close to the bottom of the pan, and so eliminate all chance of burning. As soon as the mixture boils add 14 lb. soft size, or 3 1/2 lb. common glue, 10 1/2 lb. (1 gal. and nearly 1/2 pint) water. The glue to be soaked in the water till quite soft.

In order to give the paste such qualities as shall ensure the mass keeping good for years, 4 oz. crystallised phenol (carbolic acid) are now stirred in, and all that remains to be done is to work the mixture through a sieve haying about 20 meshes to the linear inch, or it may be strained through a piece of net.

Three sorts of paper are used in making the flong. First, a fine hard tissue paper for the face; secondly, blotting paper to form the porous body; thirdly, stout and tough brown paper for the back, to give strength and to support the blows of the beating brush. It is of very great importance that the tissue paper which forms the face of the flong should be strong and fine in fibre, uniform in texture, and free from holes, all qualities which add to the expense of a paper, and any expenditure which secures the above is well bestowed, economy on this score being bad policy. A tissue which becomes pappy and soft when in contact with the paste, or which allows its exudation through holes, may cause adhesion between the forme and the mould, with the attendant delays and disadvantages. The tissue papers sold for pottery transfers are generally very suitable for stereotyping, and some makers supply a special kind. The sort sold at Lloyds paper office in Crown-court, at 11d. per lb. is made to a special size, 24 by 56 in., so as to be suitable for newspaper work.

As regards the blotting paper, the cheaper sorts answer as well as the more expensive, and I do not think the lowest priced papers contain irregularities or umps so pronounced as to be disadvantageous. Suitable demy paper, weighing 23 lb. to the ream, costs 10s. 6d. per ream.

The brown paper for the back of the flong should be made of tough, strong fibre, free from knots and lumps; moreover it should be soft, and not heavily rolled. Such a paper is expensive, costing about 4d. per lb.; but, as in the case of tissue, it is poor economy to use a backing paper of unsuitable character.

To prepare some flong, the materials will be: -

The brown paper is laid flat and pasted uniformly by means of a rather soft, flat brush, the paste being, by preference, slightly warm, on account of the glue it contains, although, with the above-mentioned proportions it is possible (though undesirable) to work it cold. A sheet of blotting is now laid on, and the pasting is repeated over each layer of paper, but in the case of the last pasting, which holds down the tissue paper, only a small quantity should be applied, and that as uniformly as practicable. A convenient way of laying down the tissue paper is to roll it on a wooden cylinder, and then to roll it off this on to the pasted surface; and all through the operation great care should be taken that no paste comes in contact with the outside face of the tissue; generally speaking, the wooden roller requires wiping after each use. Close contact of the several constituent sheets of the flong is best ensured by laying a clean paper over it after each addition, and rubbing it down with the hand, or with a cloth folded so as to form a pad. Hard rolling should be avoided, as it tends to lessen that sponginess which is so desirable a quality.

If the paste has been applied in about the light quantity, the sq. ft. of flong, the paper of which weighed about 580 gr., will, when wet and fresh, weigh about 1400 gr., about 820 gr. of this being paste; in this state it is too wet and too soft for convenient use, but if exposed to the air until something like 300 gr. of water have evaporated - that is to say, until the sq. ft. weighs about 1100 gr. - its consistency will be right for working. These weights are given principally in order that persons working from directions may be able to prepare a sample which shall have a convenient consistency, after which the remembrance of this sample should be a sufficient guide.