In surveying, the prismatic compass is used to

In surveying, the prismatic compass is primarily used to obtain bearings of features. It is a type of compass that has a prism attached to it, which allows the user to simultaneously see the compass needle and the object being sighted through the prism. By aligning the compass with the object and reading the bearing, the prismatic compass can determine the direction or angle of the object relative to magnetic north. This information is crucial for creating accurate maps and plans, as well as for navigating and orienting oneself in the field. While a prismatic compass may be capable of measuring other factors, such as horizontal distances or inclinations, its primary function is to obtain bearings of features.