| Sr.No. | Detail | Surveyor Compass | Prismatic Survey |
| 1 | Magnetic Needle | The needle is of edge bar type | The needle is a broad needle. |
| 2 | Graduated Ring | 1. The graduated ring is attached to the box and rotates along with the line of sight. | 1. The graduated ring is attached with the needle and does not rotate with the line of sight.2. The graduations have 0° at S, 90° at W, 180° at N and 270° at E (as below fig.). When the needle points north, the reading under the prism should be zero. It is so because the prism is placed exactly opposite the object vane, i.e. on the observer's side, and the south end will be under the prism while the needle points north. Hence, the Zero is placed at the south end then the ring is graduated clockwise from it3. Graduations are engraved inverted since the graduated ring is read through the prism. |
| 3 | Reading System | 1. The readings are taken directly by seeing through the top of the box glass.2. Sighting and reading cannot be done simultaneously. | 1. The readings are taken with the help of a prism, provided at the eye vane.2. Sighting and reading can be done simultaneously. |
| 4 | Tripod | The instrument cannot be used without a tripod. | The instrument can be held in hand also while making the observations. |
| 5 | Vanes | The eye vane consists of the small vane with a small slit. | The eye vane consists of a metal vane with a large slit. |
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