The Sowerby pattern books for 1895 and 1898 shown a glass swan in two sizes - large, pattern 1852, and a smaller pattern 1852½. It would seem to be an unregistered design.
The only photo of the pattern 1852 swan that I know of is a beautifully-detailed turquoise vitro-porcelain version shown as colour plate 30 in Sheilagh Murray's "Peacock and the Lions..." (Oriel Press, 1982). She gives the size as 16cm long by 12 cm high, and bearing the peacock trademark. The shape and surface detail differ significantly from the Burtles & Tate swans, and to that from Jane Webb &c.
Here are some photos of a similar swan in opalescent yellow-green uranium glass. The swan has no identifying marks. It is 15cm long x 11cm tall x 7.5cm wide, and weighs 392 gm. The uranium glass is highly reactive to UV light. The detail is not so crisp as Murray's example, but I presume that is largely due to the different working and finishing properties of the two types of glass.
(Permission to re-use these images on the GMB granted by Kevin Collins).
Does anyone have photos of the pattern 1852 swan to show in other colours, please?
Does anyone have photos of the smaller Sowerby pattern 1852½ swan to show, please?
Fred.