FORE:In constructing patterns where it is optional whether to employ cores or not, and in preparing drawings for castings which may have either a ribbed or a cored section, it is nearly always best to employ cores. The usual estimate of the difference between the cost of moulding rib and cored sections, as well as of skeleton and cored patterns, is wrong. The expense of cores is often balanced by the advantage of having an 'open mould,' that is accessible for repairs or facing, and by the greater durability and convenience of the solid patterns. Taking, for example, a column, or box frame for machinery, that might be made either with a rib or a cored section, it would at first thought seem that patterns for a cored casting would cost much more by reason of the core-boxes; but it must be remembered that in most patterns labour is the principal expense, and what is lost in the extra lumber required for a core-box or in making a solid pattern is in many cases more than represented in the greater amount of labour required to construct a rib pattern.
FORE:"Perhaps it was as well that Miss Lawrence took matters in her own hands and sent for you," he said thoughtfully. "At any rate, your presence may get us out of a certain degree of responsibility. The patient, if I may so call him, is quieter now, and you will have no difficulty with him. Of course, that is if he will see you at all. If not you will acquit us of any discourtesy."387