This is a Kew-Pattern Unifilar Magnetometer used by Professor Stuart Malin at the Royal Greenwich Observatory, Herstmonceux, and at the Geomagnetism Unit, Institute of Geological Sciences, Edinburgh.

Made of brass, wood and glass, it comes with the following attachments: theodolite base; telescope with level; long glass suspension tube with brass fittings; short brass suspension tube; magnet in box with inertia bar for Elliott 37; MSS note signed by Witchell (presumably William Moody Witchell, who worked as a computer, junior assistant and assistant at the Royal Observatory, Greenwich from 1894 to 1947); viewing tube; telescope tube and scale; silk thread on bobbin in brass box; metal box containing grease; thermometer to hang on bar; light inertia bar; metal support for magnet on bar; thermometer for magnet box; striding spirit level; two brass retaining tube; two brass plumb bobs; one magnet with mirror for deflection experiment in wooden box; theodolite tripod base, one leg containing spacer bar; all parts contained in purpose made box. Rope handles on box. There are twenty-two numbered attachments.