The economics of inspection is a subject that is rather intangible, and yet is a branch of economics which really exists and is of great importance; hence it has a proper place in this general study, because it involves a desired result to be accomplished with a minimum expenditure of effort, money, and (to a slight degree) material.

The first point to treat is this important question-To what extent will it pay the owner or promotor to have his work inspected, and how much money should be spent therefor? To this query the answer is clear and unequivocal, viz., that, within the realm of reason, the manufacture and construction of bridgework cannot well receive too thorough inspection, and the owner should be willing to pay for it a reasonable compensation to high-class men. A few dollars saved by employing cheap inspectors may mean very many dollars lost through their blundering and from lowering the value of the finished product.

Like all service functions, there should be a strong distinction between professional service at reasonable rates and simply commercial service rendered on low competitive terms. The quality of inspection is evidently dependent, as is all professional work, upon the character of the men employed, and this is unavoidably dependent upon the compensation allowed.

From the above it will be appreciated that the quality of inspection must, according to the same rule as applies to all business, be in direct proportion to its financial reward. To be of genuine value, inspection must be constant, intelligent, and complete. A final inspection may determine the satisfactory compliance with the contract, but cannot, generally, secure an adequate correction of errors; and certainly it cannot prevent them or tend to the improvement of the work. The criteria of quality of inspection are the experience of the men directly on the job, the time spent on it, and the quality of the final record. The engineer or person having the responsibility of engaging Inspecting Engineers should decide upon the experience and reputation of the firm with which he purposes dealing, should know the

* For a large portion of the data from which this chapter was prepared, the author is indebted to his friend, Mr. Watson Vredenburgh, C. E., of Hildreth & Co., one of the best-known and most successful inspecting bureaus of this country. The first part of the chapter, which is his work, relates to superstructure, while the latter portion from where the treatment of substructure begins represents the author's opinions.

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