This cross enables you to put the converter (the centre of which is obliterated by the centre screw) exactly on the chart point by making the axis lines of the 0 -180° and the 90°-270° directions coincide with the cross lines on the chart.
Umnqamlezo wenza wena ukwazi ukufaka isitshintshi kanye kwipoyinti yetshati kumgca ohamba embindini 0°-180° kunye no90°-270° inkcazelo ilingana nemigca edlula kwitshati