This meant that the observer, looking at it through a pinhole or tubular sight fixed on the opposite straight edge, could see the horizon both directly and by reflection.
Lento ithetha ukuthi abajongi, bayayijonga kwimigxunya yonotaka okanye kwikhulu lwezikhanyisi ezifakelweyo kwicala elichaseneyo nomphetho elinokubonisa ngqo kwikhondo nasekukhanyeni.