Assertion: periscope | /r/MadeOf | vertical tube
Facets:
value: at the bottom of the tube
type: LOCATION
value: with a reducing telescope
type: OTHER
value: with a head prism
type: OTHER
value: essentially
type: DEGREE
Source sentences:
text: Essentially, a periscope consists of a vertical tube with a head prism inclined to the horizon at an angle of 45 degrees, a reducing telescope, and, at the bottom of the tube, an enlarging telescope and a lower prism facing the head prism and parallel to and below it.