159mm (length), lignum vitae with brass fittings and good optics.

This stunning little telescope or 'prospect glass' is similar in design to the famous 'little perspective' advertised in John Yarwell's late-17th century trade card. A similar example is held at the Science Museum, London, where it is dated c.1750 (inv. no. 1918-142); another is in the Louwman Collection of Historic Telescopes where it is dated c.1700. Little research has been carried out on this particular design, and an earlier date – potentially even late-17th century – seems likely.

Galilean optics: bi-convex objective lens and plano-concave eyepiece (as with the two other examples just mentioned).

Condition is excellent: the optics are working and can be removed for examination. Focus is by a crude central screw. Magnification is low but the image produced is clear and distinct. The surface of the wood is nicely polished, noting only a few scratches; brass caps and lens holders are somewhat tarnished.