Chapter CXV: Section 11: provides that "the enlisted force of the Corps of

Engineers shall consist of one band and three battalions of
engineers. … Each battalion of engineers shall consist of one
sergeant-major, one quartermaster-sergeant, and four
companies. Each company of engineers shall consist of one
first sergeant, one quartermaster-sergeant, with the rank,
pay, and allowances of sergeant, eight sergeants, ten
corporals, two musicians, two cooks, thirty-eight first-class
and thirty-eight second-class privates."