from The Century Dictionary and Cyclopedia
- n. The inhabitants of the polar circles: so called because in their summer-time their shadows describe an oval.
In regions where the sun remains above the horizon during an entire revolution of the earth, the shadow must evidently have turned in a complete circle round the gnomon. On this account he named them periscii.
The Periscii are those who may live in the frigid zone either north or south; and as the sun moves around them when in their summer months, without setting, their shadows are cast in turn to every point of the compass.
‘Periscii’ comes from a Greek word meaning ‘throwing a shadow all around.’