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Show TH PRINCIPLE O SCIENTIFI MANAGEMEN 5 sufficient practical information had been obtained to far more tha repay the -cost of materials and wages which had been expended i experimenting And yet the comparatively small number of experiments which had been made served principally to make it clear tha the actual knowledge attained was but a small fraction of that whic still remained to be developed, and which was badly needed by us in our daily attempt to direct and help the machinists in thei tasks Experiments in this field were carried on, with occasional. interruption, through a period of about 26 years, in the course of which te different experimental machines were especially fitted up to d this work Between 30,000 and 50,000 experiments were carefull recorded, and many other experiments were made, of which no recor was kept In studying these laws more than 800,000 pounds o steel and iron was cut up into chips with the experimental tools and it is estimated that from $150,000 to $200,000 was spent in th investigation Work of this character is intensely interesting to any one who ha any love for scientific research For the purpose of this paper however, it should be fully appreciated that the motive power whic kept these experiments going through many years, and which supplie the money and the opportunity for their accomplishment, was no an abstract search after scientific knowledge, but was the ver practical fact that we lacked the exact information which was neede every day, in order to help our machinists to do their work in th best way and in the quickest time All of these experiments were made to enable us to answer correctl the two questions which face every machinist each time that he doe a piece of work in a metal-cutting machine, such as a lathe, planer These two questions are drill press, or milling machine In order to do the work in the quickest time At what cutting speed shall T run my machine? an What feed shall T use They sound so simple that they would appear to call for merel the trained judgment of any good mechanic. In fact, however after working 26 years, it has been found that the answer in ever case involves the solution of an intricate mathematical problem, i which the effect of twelve independent variables must be determined Each of the twelve following variables has an important effec upo th answer Th figures whic ar give wit eac of th variables represent the effect of this element upon the cuttin For example, after the first variable (A) we quote, "Th speed |