First. He has entirely dispensed with certain movements which the bricklayers in the past believed were necessary, but which a careful study and trial on his part have shown to be useless.
Second. He has introduced simple apparatus, such as his adjustable scaffold and his packets for holding the bricks, by means of which, with a very small amount of cooperation from a cheap laborer, he entirely eliminates a lot of tiresome and time-consuming motions which are necessary for the bricklayer who lacks the scaffold and the packet.
Third. He teaches his bricklayers to make simple motions with both hands at the same time, where before they completed a motion with the right hand and followed it later with one from the left hand.
For example, Mr. Gilbreth teaches his bricklayer to pick up a brick in the left hand at the same instant that he takes a trowelful of mortar with the right hand. This work with two hands at the same time is, of course, made possible by substituting a deep mortar box for the old mortar board (on which the mortar spread out so thin that a step or two had to be taken to reach it) and then placing the mortar box and the brick pile close together, and at the proper height on his new scaffold.
These three kinds of improvements are typical of the ways in which needless motions can be entirely eliminated and quicker types of movements substituted for slow movements when scientific motion study, as Mr. Gilbreth calls his analysis, time study,
