214 LAWS OF MARYLAND [CH. 8

ing, moving, or transporting of materials from one machine
to another or from one part of a plant to another; the piling,
stacking, or arranging of materials for feeding into a ma-
chine by another person; and the sorting, tying, bundling, or
loading of materials.

(c) No minor under 18 years of age shall perform any
work in any workroom in which:

(1) Radium is stored or used in the manufacture of self-
luminous compound.

(2) Self-luminous compound is made, processed or pack-
aged.

(3) Self-luminous compound is stored, used or worked
upon, or

(4) Incandescent mantels are made from fabric and solu-
tions containing thorium salts, or are processed or packaged.

(d) Definitions. The term "self-luminous compound" shall
mean any mixture of phosphorescent material and radium,
mesothorium, or other radio-active element.

The term "workroom" shall include the entire area bound-
ed by walls of solid material and extending from floor to
ceiling.

16. (a) No minor under 18 years of age shall be permitted
to work at the following occupations involved in the opera-
tion of power-driven hoisting apparatus:

(1) Work of operating an elevator, crane, derrick, hoist,
or high-lift truck, except operating an unattended automatic
operation passenger elevator or an electric or air-operated
hoist not exceeding one ton capacity.

(2) Work which involves riding on a freight elevator
(where employees are customarily transported to their work
place at the beginning and end of scheduled work periods in
a freight elevator operated by an assigned operator, such rid-
ing shall not be considered as ivork within the intent of this
paragraph).

(3) Work of assisting in the operation of a crane, derrick,
or hoist performed by crane hookers, crane chasers, hookers-
on, riggers, rigger helpers and like occupations.

(b) Definitions. The term "elevator" shall mean any
power-driven hoisting or lowering mechanism equipped with
a car or platform ivhich moves in guides in a substantially
vertical direction. The term shall include both passenger and