This need not remain forever true. Because there is not in general use any intelligent or accurate method of determining whether or not any one of these unskilled, untrained workers possesses the elementary mental capacities requisite for a particular sort of employment, it is not surprising that most of them fail to make good in the jobs into which they are indiscriminately shovelled. Yet the great majority of them do possess mental capacity of a nature and degree which, once it is ascertained, indicates their definite fitness for some particular sort of work no less than it does their definite unfitness for many other kinds of work which they are prone to undertake. Just as war conditions brought into the Army an enormous mass of young men whose capacity and special abilities had to be determined by scientific tests before they could be assigned to the places where they could most usefully serve in the military scheme of things, so the same exigency of war brought into the industries of the country, largely centred upon the production of munitions of war, millions of women without industrial experience or vocational training but upon whose efforts the nation had mainly to rely for the output of weapons, ammunition, military equipment and accessories without which the Army and Navy could not have functioned. In a large class of plants engaged in munition production the chief demand was for sufficient muscular strength, with a slight modicum of intelligence, for the operation of automatic machinery. But in the vitally important work of inspecting, testing, and sorting the finished product of even the most highly perfected automatic machines and in many of the more delicate operations of assembling and adjusting devices and apparatus made up of a number of more or less complicated parts, intelligence and mental capacity of several different kinds and ranging up to fairly high degrees were called for. In a number of the larger munitions establishments scientific mental tests were adopted for the selection and assignment to particular tasks of the women workers. Wherever this was done it was found that the output was increased, a higher average of quality maintained, and the labour turnover greatly reduced. In one of the largest groups of munitions plants at Bridgeport, Conn., there was worked out, under the direction of Dr. Henry C. Link, a system of scientific mental tests which checked up so closely with the actual results obtained by the most skilful workers that their adoption for the examination of all applicants for these positions resulted in very definite time and money savings and increase in plant efficiency.