Surveyor's cross with central compass. Silvered bilevel compass with 8 point rose, 0-90-0-90-0° every 10°, and 0-360° every 1°. East and west points reversed. Flat bar needle type 62; jewelled pivot. Needle brake. Compass box rotates on top of crossed arms bearing 4 sight vanes. A pair of slit-and-window sights on each vane.
