Nine inch ebony octant, London.

Octant, late 18th century.

Electrotherapy machine, Europe, 1862.

Octant, 1791.

Electrotherapy machine, Europe, 1862.

An octant designed by Hadley, c 1730.

Naval officer using an octant, late 18th century.

Improved patent magneto-electric machine for nervous diseases, 1862.

Octant, 1850-1870.

Basilyst

Bromide print, from Hevelius's "Machina

Brass divination bowl, Middle East, 1851-1920.