concrete workers to-day, and by them has been held a secret, yet it has been employed in a desultory manner by such as knew how to employ it, for a number of years. In this the first complete explanation of this valuable process I shall present the various ways of employing the system to produce a wide range of work; such as is needed by the every-day worker in his daily employment; giving the most practical and easiest ways of securing the desired results.

All concrete men are agreed upon the fact that for many purposes the wet mixture of concrete has advantages over a semi-moist mixture; in this work the molds permit either a very wet mixture or one that is just wet enough so it does not have to be tamped, and in event the molds are baked or hardened the concrete placed in same may be lightly rammed or tamped and a semi-moist mixture employed. The best results are obtained when the mold is filled with liquid concrete or so that it may be poured into the mold; the sand absorbs the excess moisture in the concrete and this dries

out slowly, thus retarding the "set" or hardening of the concrete and removing all necessity of sprinkling the work or covering with wet blankets while "green," thus giving the maximum of strength with the minimum of labor and cost.

Where there is much under-cutting or an ornament which overhangs, giving a deep hollow beneath same, this process is of the greatest value when it is necessary to remove the work from the molds; the sand when unbaked and the moisture has evaporated from same, is easily separable into small pieces, so that the portion of the mold which is in the hollow, or the core, simply breaks into small grains again and is removed without the least danger of injury to the work molded. These cores can be made a part of the mold; made at the same time as the impression of pattern is taken or they may be made separately, as in the event of intricate and deep hollows in the work that require a core that would not hold for the removal of the pattern; by forming these as a separate unit and adding to the mold, work may be pro

duced that cannot be accomplished in any other mold in use to-day.

The surface finish of concrete to-day as molded in the ordinary wood and metal molds is far from perfect when considered from the standpoint of beauty; the coating of the outside face or particles of aggregate with cement, gives to the work an appearance of dullness, or lifelessness, as compared with the sparkle and luster of the grains of natural stone; when this is remedied by the use of acids, the restoration is not complete and the method is laborious and expensive. With the sand mold process the face of the mold may be composed of crushed granite, white sand, marble flour, or any extra facing you may wish; this simply retains its shape until the mortar is poured into the mold and is a separate part of the mold, thus permitting the facing material to become a part of the finished work free from any coating of cement upon its face; thus producing work that has all the beauty of natural stone in every way.

Another advantage is the great adaptability

of the process to every style of work that it is desired to produce; the requisite of a pattern is supplied by the wood pattern, clay model, cut or cast stone, or even many other articles that give the desired shape; it is thus possible for the worker to secure a mold to suit his own ideas and desires as he has the use of many patterns and can build them up to perfect the design he may wish to mold in concrete, from various units thus making the range of work within his power practically without limit.

In addition to the foregoing arguments that make this process appeal to every concrete worker, the item of cost is one that cannot be overlooked. In the wood and metal molds that are offered the worker to-day, the first expense is very large; it requires that a number of pieces be produced and sold to repay the initial outlay, which in many cases is not practicable. In molding varying sizes of any piece a separate mold is required that often makes the cost prohibitive and the result is that something else is substituted with a loss in appearance.

With this process a pattern and sand are the

requirements of as many molds as you desire or your work demands; the cost in comparison to any other form of mold is so slight as to be hardly worth considering, thus permitting a free rein to the wishes of the worker as to size, style and variety of the molds he wishes to use, without the expense and bother of moving from place to place a vast number of cumbersome molds.