The Horne & Thornthwaite Tailboard Camera is a Victorian-era British wooden-bodied plate camera of the tailboard type, in which the rear standard slides along a hinged baseboard that drops down for use. Horne & Thornthwaite was a 19th-century London optical and photographic supplier, and tailboard cameras of this kind were typical studio and field instruments of the wet-plate and early dry-plate periods.

Auction evidence for this maker's tailboard cameras is thin: the two UK hammer results on file, both from a Christie's sale on 17 February 2004, sold for £119 and £262, giving a median around £190. Because these are saleroom hammer prices rather than dealer retail, today's value for a comparable example sits broadly in that £120–£260 range, with condition of the bellows, woodwork and any original brass-bound lens being the main price drivers.