motions of his bricklayers from eighteen to five shows that this
improvement has been made in three different ways:

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 brick-layer 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 brick-layer to pick up a brick in
the left hand at the same instant that he takes a trowel full 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, as the writer has called
similar work, are, applied in any trade.