An accurately balanced magnetic needle, strongly magnetised, is fitted with hardened steel pivot working in jewels cup bearings. The needle can be easily removed for reversal. The inclination scale is of chrome brass graduated in degrees 0 to 90 four times. The case is made of non magnetic cast alloy, duco painted; has easily removable plate glass window & rotates fully on a heavy brass base, its rotation being measured by a brass chrome dial reading 0 to 360º. Its fitted with levelling screw & sprit level.