found: Autograph letters signed from Thomas Carlyle to various people, 1838-1853(John William Parker)
found: Oxford DNB, June 2, 2014(under Parker, John William (1792-1870), publisher and printer: Parker's son, John William Parker, born 1820; educated at King's College, Cambridge, joined his father's firm as general manager in 1843 (the firm, John W. Parker, at 445 Strand, London, then became John W. Parker & Sons, and a few years later John W. Parker & Son); editor of Fraser's magazine for town and country; died on 9 Nov. 1860)
found: Gentleman's magazine, Feb. 1861, via Google Books, June 2, 2014:pages 221-224 (obituary: Mr. John William Parker, Jun., publisher, of West Strand [London]; died Nov. 9, 1860, aged 40; publisher and magazine editor)
found: Fraser's magazine for town and country, Dec. 1860, via HathiTrust, June 2, 2014:pages 810-813 (in memoriam: Mr. John William Parker, Jun.; John Parker)
found: Rules of the Photographic Society Club, 1856:leaf 5 recto (list of club members, including "John W. Parker, Esq.") leaf 21 (portrait of a dark-haired balding man in his 30s to 40s, wearing spectacles, as in the Wellcome Library image from a copy of this work, cited below; inscription beneath portrait in NN copy: "J.W. Parker")
found: Wellcome Library/Wellcome Images online cat. June 2, 2014(in record for "J.W. Parker. Photograph," 1856: "The subject may be the publisher and printer John William Parker (1792-1870) or his son of the same name (1820-1860)"; image shows a man in his 30s to 40s) - http://wellcomeimages.org/indexplus/image/V0028363.html
found: Journal of the Photographic Society, July 21, 1856, via Nineteenth Century Collections Online, June 9, 2014:page 76 (in minutes of a "special general meeting" of the Photographic Society, July 3, 1856: "The following gentlemen were ... duly elected members: ... J.W. Parker, Jun.")