10. Printing, photo-engraving, stereotyping, electrotyping,
lithographing, embossing; manufacture of stationery, paper,
cardboard boxes, bags, or wall paper, and book-binding.

41. The operation, otherwise than on tracks, on streets,
highways, or elsewhere of cars, trucks, wagons or other
vehicles, and rollers and engines, propelled by steam, gas,
gasoline, electric, mechanical or other power.

42. Stone cutting or dressing; marble works; manufacture
of artificial stone; steel building and bridge construction; in-
stallation of elevators, fire escapes, boilers, engines or heavy
machinery; brick-laying, tile-laying, mason work, stone set-
ting, concrete work, plastering; and manufacture of concrete
blocks; structural carpentry: painting, decorating or reno-
vating; sheet metal work; roofing; construction, repair and
demolition of buildings and bridges; plumbing, sanitary or
heatmg engineering; installation and covering of pipes or
boilers.

43. In addition to the employments set out in the preced-
ing paragraphs, this Act is intended to apply to all extra-
hazardous employments not specifically enumerated herein.

SEC. 33. Any employer, his employee or employees en-
gaged in works not extra-hazardous within the meaning of this
Act may, by their joint election, filed with the Commission, ac-
cept the provisions of this Act and such acceptances when ap-
proved by the Commission, shall subject them to the provisions
of this Act to all intents and purposes as if they had been
originally included in its terms.

Any workman, of the age of sixteen years and upwards may
himself exercise the election hereby authorized. The right of
election hereby authorized shall be exercised on behalf of any
workman under the age of sixteen years by his parent or
guardian. Nothing herein shall be construed to apply to
workmen of less than the minimum age prescribed by law for
the employment of minors in the occupation in which such
workman shall be engaged.

The provisions of this Act shall apply to employers and
employees engaged in intra-state and also in inter-state or
foreign commerce, for whom a rule of liability or method of
compensation has been or may be established by the Congress
of the United States, only to the extent that their mutual con-
nection with intra-state work may and shall be clearly separ-
able and distinguishable from inter-state or foreign commerce,
except that any such employer and any of his workmen only