The wings of the lantern controlled the number and angles of the beams. Given the huge number of different lighting requirements of roads and their environs, a large number of differently configured wing type lanterns were produced. These differed in the number of wings and the angles of the beam; it wasn't uncommon to find many different lanterns lighting a single stretch of road.

The first type of wing lantern, due to Harrison, used facetted, mirrored glass pieces stuck to a cast-iron frame (and he held the patent for the method of arranging and sticking them). Other manufacturers also produced wing type lanterns; but elected to use polished enamel surfaces, curved etched and fluted glass, and/or glass strips held by metal lugs in order to side-step the patent.

Whilst the utilization factor was lower than other lanterns (due to little flux being collected above the lantern), and glare from the totally exposed bulb was an issue, wing type lanterns became popular for their sheer robustness, minimal number of parts and cheapness.

The design of the wing type lantern changed little over the next thirty years. Although open lanterns were frowned upon by the mid-1950s (as no protection was afforded to the bulb nor the reflective surface so both got dirty and required regular cleaning), wing type lanterns were still being installed in the 1960s; but in the end, discharge lamps and the benefits of enclosed lanterns saw their eventual downfall.

This lantern was an eBay win so I have no idea of its previous history. I suspect (given its general condition, the Lucy swan-neck, and the collection address in Surrey) that it was part of "the horde" - a large collection of lanterns and swan-necks secured in a barn and only recently sold on.

The mirrors were are in surprisingly good condition with about 80% still remaining. The swan-neck is also in fairly good condition although the Lucy fuse box was smashed when the lantern was removed.

I shall either replace the fuse box or put the lantern on a different swan-neck.