Applied Motion Study
A Collection Method to industrial Preparedness

62 APPLIED MOTION STUDY jection to the use of these methods and devices is their variation from accuracy, due to the human element. This is especially true of the use of the stop-watch, where the reaction time of the ob- server is an element constantly affecting the ac- curacy of the records. But the greatest loss and defect of personally observed and recorded times is that they do not show the attending conditions of the varying surroundings, equipment and tools that cause the differences in the time records, and give no clue to causes of shortest or quickest times. As for motion study, Marey, with no thought of motion study in our present use of the term in his mind, developed, as one line of his multi- tudinous activities, a method of recording paths of motions, but never succeeded in his effort to record direction of motions photographically. Being unable to find any devices anywhere such as the work of our motion study. required, the problem that presented itself, then, to us who needed and desired instruments of precision, ap- plicable to our motion study and to our time study, was to invent, design and construct devices that would overcome lacks in the early and ex-