This deviation from the known charted magnetic north is either added to or subtracted from the angle of variation before conversion of the compass readings to chart meridians.
Oku kuphambuka ukusuka kukwenziwa kwetshati kamazibuthe kumntla mhlawumbi kudityaniswe okanye kuthatyathwe ukusuka kwi-engile yeendidi phambi kokutshintshwa kofundo lwekhampasi kwiMerdiyani yetshati.