Dr. Lorimer's dipping compass. An octagonal wooden box from out of which projects four intersecting brass rings perpendicular to each other and incised with degree scales. Suspended in the innermost ring, which is oriented upright, is a needle which can rotate freely inside the ring.

ABDNP:200013a

Instrument for showing that a compass needle not only points to magnetic north but if freely suspended will point into the ground. This later phenomenon is known as the 'dip' of the compass needle. Horizontal scale 0 -90 in 1/20 on either side of N and S points. (Thus exceeding S 53.15 W). Vertical scale marked all round inside of inner circle in 1 degree intervals with 10 reading digits on scale of inner circle. Compass on double gimbals. Top section of octagonal box (with inscription plate) rotates about a central vertical axis defined by a brass bearing between box and base plate. Base plate has 3 small five-toed feet. 'Univ. Abdn. Nat. Phil.' embedded circular disk.

Inscribed: 'Instrumentum hocce Navalem ad rem atque Philosophican percutile Ioan Lorimer M.D ingenio excogitatum. Academiae Marischallanae Abredonensi grato animo erga Almam Matrem Inventor ipse dono dedit A.D. 1795'

Dr. John Lorimer

1764

wood, brass, glass

Physical Object