Sir – On page 28 (October 22) is published a photograph by Helen Fairweather of what is labelled as “A gargoyle outside the Sheldonian Theatre in Broad Street” with “a garish makeover in the shape of pink lipstick”. The Concise Oxford Dictionary defines gargoyle as “a grotesque carved human or animal face or figure projecting from the gutter of (especially a Gothic) building, usually as a spout to carry water clear of a wall”.

What Helen Fairweather photographed is not a gargoyle, but one of the 13 Sheldonian “herms” which the hyper-gifted Oxford sculptor, Michael Black, with the help of two assistants, carved between 1970 and 1972, as replacements for two earlier sets of heads, from 1662-8 and 1868 respectively; another four of Black’s replacement heads stand outside the Museum of the History of Science. The 17 herms have variously been described as emperors, philosophers, and apostles.

The sculptor and designer Michael Black, whose extraordinary career richly merits celebration here in Oxford and beyond, based the design of his heads on a contemporary engraving of the first set of herms by the Polish-born British artist and engraver, David Loggan (1635-1692).

Bruce Ross-Smith, Headington