What is the difference between a sofa and a settee?

In practice, nothing. Dealers use sofa, settee and couch for the same long upholstered seat, and settee alone appears in 235 titles on Sellingantiques against 64 for couch. The useful distinction is elsewhere: whether the frame timber shows, and whether the piece has one raised end or two.

Why do some listings say chaise lounge?

It's a common alternative spelling. Of the 259 titles using chaise, 194 read chaise longue and 51 read chaise lounge. Both describe the same thing: a long seat with one raised end for reclining. Day bed and daybed also turn up for the form.

Which timbers do show-wood frames use?

Three dominate. Mahogany appears in 229 titles, walnut in 196 and rosewood in 81. Oak is a distant fourth at 23. Ebonised frames, stained and polished black and often with gilt lines, run through the Aesthetic-influenced pieces.

How precisely are these dated?

Loosely, for the most part. More than half the archive carries no year at all: 453 listings are labelled simply Victorian and 118 only 19th Century. Where decades are given, the 1880s lead with 158 listings, ahead of the 1860s, 1890s, 1850s and 1870s. The clean-year field spans 1800 to 1930, but the weight sits mid to late nineteenth century.

Are chesterfields always leather?

No. Leather appears in 82 titles and leather chesterfield in 30, so a good many chesterfields are listed in fabric or velvet instead. What the name signals is the form: arms level or nearly level with the back, and buttoning drawn deep into the upholstery.

What unusual forms turn up in this category?

Beyond the mainstream, window seats, hall benches, settles and conversation seats appear at the fringes, the last with sitters facing different ways. One-offs include a miniature ebonised chaise, a bath tub chaise, an Anglo-Indian carved sofa, an Austro-Hungarian shell-shaped sofa, a swivel conversational sofa and a chaise with concealed storage. Country-house framing is its own sub-language, used in 47 titles, taking in Knole sofas and a billiard-room sofa.