Alfred Domett, Browning's fellow poet and friend from their early days together, records several visits with the senior Thornycrofts after his return to England from New Zealand in 1872, where he had lived for several decades. His diary for April 18, 1873 mentions dining at a friend's home. when “the Thornycrofts were there &c. Mrs. Thornycroft with her silver hair, intellectual and kindly motherly look, so pleasing and unassuming" (81). His diary entries between 1872 and 1883 record conversations with Mary and mention her works, particularly for the royal family. His diary also provides information about her views of sculpture and individual sculptors, such as J. E. Boehm, whose work she thought too "realistic." In his diary entry for March 21, 1877, for example, Domett notes that "Mrs. T., perhaps of course, thought Sculpture not sufficiently 'patronised' in England. But judging by the number of busts in the Exhibition every year, and the proportion they most probably bear to the unexhibited ones, portrait sculpture at least must be pretty well encouraged; and ideal sculpture of much excellence must necessarily be very rare" (185).
In his diary Domett — the original of Waring in Browning's poem, "What became of Waring?" — also provides interesting information about Mary's commissions and contact with the royal family. His entry for May 8, 1874 thus mentions that the Thornycrofts :dined with us. She was doing busts of two of the Princesses then, Pss Louise had been a pupil of hers — used to come, often on foot, to her studio from Marlboro' House for her 'lessons.' Mrs. T. had often stood the Prince of Wales on a table." Domett comments that she “would be puzzled to do it now &c. &c. portly as he is getting" (124). And then we learn: "Mrs. Thornycroft says Princess Louise, sitting once for her bust, in a self-deprecating way remarked, 'I always had a potatoe nose!'" (132).
According to Domett, this kind of familarity influenced the sculptors' choice of home and studio. In fact, the Thornycrofts chose their residence to be nearer the royal family at the Prince Consort's request: "Mrs. T said they paid £200 a year rent for their house, 21 Wilton Place! Came there because Prince Albert used to say to Thornycroft when they lived at Stanhope St. Regent Park 'You are too much out of the way'" (134). His entry for March 21, 1877 contains more interesting information about her work for the Royal family:
MAR. 21. Called at the Thornycrofts'. Mrs. T. at home. Shewed me her bust of the Duchess of Edinburgh. As usual with her portraits it looks dignified and simple. She says the Queen has ordered her to make busts of the three children (princesses) daughters of Princess Alexandra, for Osborne. The Queen on these occasions merely gives an order for the work to be done; she (Mrs. T.) then sends in her charge to the Keeper of Privy Purse, has always found payment made without any trouble or delay as to forms &c, but always makes precisely the same charge to the Queen she would make for similar work to any other person of whatever rank. In this case, the busts being for special niches at Osborne, they sent her very particular measurements of the size of each, but after all sent for her to the Isle of Wight that she might see the effects of light and shadow her busts should be suited to. The Duchess of Edinboro', she says, has a very clear complexion and bright eyes, and a 'baby' mouth. In the bust the lips, though full are very well-shaped. 
Later in the same diary entry, Domett records Mrs. Thornycroft's perhaps surprising attitude toward a sculptor's actually chiseling stone:
She seemed to think it 'affectation' in a sculptor, working at or 'touching' the marble himself. In this she agrees with her husband. And yet it is difficult to conceive how the niceties of expression in a face, for instance, can be mechanically reproduced in marble, by measurement from the plaister or clay model applied to a marble block, even though the depths of borings, from the rough outside of the block down to the required surface of the face or figure it is to be cut away to, be precisely ascertained to as many as eight points in every square inch of such surface, as Thornycroft once told me was about the number usually made. It stands to reason that the expression in such cases, must ultimately be given by or depend upon the marble-worker's own power of copying accurately from the plaister model. But if this sort of skill is to be exercised should not some of the credit of producing work be given to the mechanic? 
Mary and Thomas Thornycroft's attitude derives directly from the widespread class-based desire to divorce the activity of the sculptor from that of manual laborer — an attitude also evident at the heart of Renaissance and eighteenth-century attempts to elevate the status of the painter by appeals to ut pictura poesis that emphasized the mental work of the artist. Domett's sensible reaction to the views of both husband and wife remind us both that nineteenth-century sculptors employed assistants and the great degree to which these assistants should be seen as co-creators rather than as subservient laborers.
What strikes me as especially surprising here involves matters of gender. First of all, both husband and wife believe the person who receives credit as the creator of a piece of sculpture should not work on the actual marble. Second, the strength needed to chisel stone served as the single most important argument why Victorian women could not become sculptors. (Working from nude models was another.) One solution to this apparently paradoxical situation in which lack of strength supposedly prevented women from becoming sculptors when male sculptors did not actually have to employ their strength might lie in the fact that many sculptors early in their careers worked as studio assistants, and women supposedly would not be able to have that experience. At any rate, in the late nineteenth century the popularity of bronze sculpture based upon clay models removed the gender barrier, quickly producing large number of women working in this three-dimensional art.
British Sculpture 1850-1914. A loan exhibition of sculpture and medals sponsored by The Victorian Society. London: Fine Art Society, 1968.
The Diary of Alfred Domett, 1872-1885. Ed. E. A. Horsman. London: Geoffrey Cumberledge/Oxford University Peress, 1953.
Mass, Jeremy. The Victorian Art World in Photographs. London: Barrie & Jenkins, 1984. P. 212.
Last modified 17 February 2020