Final answer:
The purpose of the M51 Instrumental Light for the m² Aiming Circle is to provide illumination and assist in aligning and targeting specific points or objects with greater accuracy in surveying and artillery.
Step-by-step explanation:
The purpose of the M51 Instrumental Light for the m² Aiming Circle is to provide illumination for the aiming circle. The instrumental light helps the user align and target specific points or objects with greater accuracy. It is an important tool in surveying and artillery, allowing for precise measurement and targeting.