If the instrument is to measure all angles correctly, the Index and Horizon mirrors must at all times be perpendicular to the plane of the sextant.
Ukuba isixhobo sifuneka silinganise zonke iimbombo ngendlela eyiyo, isalathiso nezipili zolundi mazisoloko ngalo lonke ixesha zithi nkqo kwinqwelo-moya yesixhobo sokulinganisa ukuphakama kwelanga ukufumano ubuphi benqanawa.