Outline of the Changes to Be Made.
It became apparent, as the work progressed, that the determining elements were (1) to shorten, as far as possible, the distance for transporting the arms and hands while loaded; (2) to arrange the parts so that their sequence of use would be obvious; (3) to position each piece so that it could be grasped, transported, and released in the shortest time with the least expenditure of effort and with the least resulting fatigue. This meant that the parts should be arranged on some sort of a holder, or packet, that would shorten the transporting distance, and that the base group should be placed upon a table that would carry it as near this packet as possible.
The Solution of the Problem.
A packet, which was practically a table with its top extending vertically, was placed near the table supporting the base group, and removable wire rods of the right length were placed in it to support the various pieces in the best position for grasping. This also considered the shortest distance for transporting the arms and hands, whether empty or loaded. These table packets were then modified, following closely the principles of the design of the brick packet, especially the hand-hole feature for firm grasping with one motion and for quick counting of the number of pieces. The packets now consist of strips of wood two inches apart, horizontally, and two inches apart, vertically, with holes for pins, interchangeable wire rods, forked hooks, and other hangers, including interchangeable platforms, shelves, and vertical supports, extended and positioned for still shorter reach, and holding in turn such devices as pins to permit the best position for handful grasping without disturbing the motions of the hand or the wrist from the natural position, or, that is, the position most resembling that of normal rest.
The right position for grasping anything with least fatigue is that position that will permit grasping without turning, twisting, or holding the wrist at all from its natural resting position, that is, with muscles in natural balance. It is but natural that this should be the best way, for it cuts out the positioning motions of the hand prior to grasping.
Two reasons that the strips of wood were made two inches apart, horizontally, and two inches apart, vertically, were:
1. Because we desired to get standard data at the same time comparable with our other standard data. We might also use it for checking, by means of motions in another trade, the underlying laws of motions, which we had already deduced in several other trades.
2. Because we desired to have the motions in very nearly the same places every time, in order to get the extra efficiency and the lesser fatigue that come from the habit that is formed in this reaching and grasping.
Many of these laws have since been re-checked and used in methods of least waste for the transference of skill from one trade to another. Habits have been formed that permit a much greater amount of output with less fatigue.
This latticed packet gives us the same dimensions as our cross-sectioned background. We use four inches in our American work, and ten centimetres in our European work for these distances—the difference between ten centimetres and four inches being almost exactly one-sixteenth of an inch, or so small a difference as to be practically negligible in work on motion study.