数量iv, 94, v p. : ill., plans ; 24 cm.
一般注記"Prepared by Anice L. Whitney"--p. ii.
At head of title: U.S. Department of labor. James J. Davis, secreatry. Bureau of labor statistics, Ethelbert Stewart, commissioner.
Plates printed on both sides.
Issued also as House doc. 62, 70th Cong., 1st sess.
A similar study made in 1916-17 was issued as Bulletin no. 250 of the United States Bureau of labor statistics.