Burton's translation was one of two unabridged and unexpurgated English translations done in the 1880s; the first was by John Payne, under the title "The Book of the Thousand Nights and One Night" (1882–1884, nine volumes). Burton's ten volume version was published almost immediately afterward with a slightly different title. This, along with the fact that Burton closely advised Payne and partially based his books on Payne's, led later to charges of plagiarism. Owing to the sexual imagery in the source texts (which Burton made a special study of, adding extensive footnotes and appendices on "Oriental" sexual mores) and to the strict Victorian laws on obscene material, both translations were printed as private editions for subscribers only, rather than being published in the usual manner. Burton's original ten volumes were followed by a further six entitled The Supplemental Nights to the Thousand Nights and a Night (1886–1888). Burton's 16 volumes, while boasting many prominent admirers, have been criticised for their "archaic language and extravagant idiom" and "obsessive focus on sexuality"; they have even been called an "eccentric ego-trip" and a "highly personal reworking of the text". His voluminous and obscurely detailed notes and appendices have been characterised as “obtrusive, kinky and highly personal”.