(This costume description predates the Co-Freemasonry movement that began on the European continent in the 1880s. It is probably meant as a futuristic fantasy costume, rather like the Footwoman of the Future.)
FREEMASON, FEMALE. Black velvet dress; white satin Watteau sacque, trimmed with swansdown; swansdown ruff at throat; hair powdered; quaint velvet hood, studded with pearls and Masonic emblems; a Master Mason's apron and collar of office, with pendant gauntlets and Masonic jewels; clock at girdle.
Other than the earliest edition not capitalizing "Mason" or "Masonic", the descriptions are identical throughout across sixteen years and three editions of a single manual.
The costume is a poudré (powdered) one; see With Regard to Powdering for instructions on how to powder the hair for such costumes.
Oddly enough, there was a female Freemason in the eighteenth century, Elizabeth Aldworth, whose portrait may be seen at left. Her clothing is considerably less elaborate than the swansdown-trimmed outfit described above, and her hair is not powdered, but the apron is present, and she is pointing to a Masonic symbol in the book next to her.
Holt, Ardern. Fancy Dresses Described, 2nd Edition, Illustrated. London: Debenham & Freebody, 1880.
Holt, Ardern. Fancy Dresses Described, 5th Edition. London: Debenham & Freebody, 1887.
Holt, Ardern. Fancy Dresses Described, Sixth Edition. London: Debenham & Freebody, 1896.
The 1896 edition of Holt may be found online at the University of Wisconsin Digital Collections.