GRYLLS, Humphrey John Maxwell (1865-1942), partner in the successful Detroit, Mich. architectural firm of Smith, Hinchman & Grylls, founded in 1908 and still active today under the name of SmithGroup, Architects & Engineers. The roots of this Detroit firm extend back in time to 1853, making it one of the oldest architectural offices still in existence in North America (see main entry under Frederick Smith). Grylls was born in Liskeard, Co. Cornwall, England on 8 March 1865 and emigrated to the United States in 1883. He settled in Detroit and trained under W.E. Brown and, from 1889 to 1900, as a draftsman, and later as partner, with John Scott, a leading architect in that city.
From 1900 to 1904, Grylls worked under his own name, and in 1904 he was credited with the design of The Davis Block, Sandwich Street East near Ouellette Avenue, WINDSOR, ONT. (Evening Record [Windsor], 17 Dec. 1904, 13, extensive descrip.). This project involved the dramatic transformation of the old Opera House Block into a new commercial office block, complete with a new façade and new interiors. In 1905, he was referred to as "...the Detroit architect Mr. Drills" [sic], who designed a new facade for the Joseph Appelbe & Co retail block, also located on Sandwich Street East near Ouellette Avenue, WINDSOR, ONT. (Evening Record [Windsor], 13 July 1905, 5).
In 1908, Grylls was invited to join in a partnership with Fred L. Smith (1862-1941) and Theodore H. Hinchman Jr., and together their office had a major impact upon the architecture of Detroit and southern Michigan. Grylls later died in Detroit on 21 June 1942 (obituary & port. Detroit Free Press, 22 June 1942, 17; New York Times, 22 June 1942, 15; biog. H. Withey, Biographical Dictionary of American Architects, 1956, 252).