With the Seville orange crop in doubt, as reported by the Observer, I suggest that all we marmalade makers in our 80s turn now to crab apple jelly. My tree has produced a good crop of little, yellow fruit, which becomes a slightly sharp, clear, pink jelly. It is excellent on toast and is the easiest jam to make as it sets very easily every time.
• Your article (‘The more dangerous the operation, the more I wanted to do it’, 5 October) says Henry Marsh “pioneered a type of neurosurgery in which the patient is awake”. As a student nurse, I watched Prof Norman Dott practise this type of surgery in 1957 at Edinburgh Royal Infirmary.
Hamilton, South Lanarkshire
• Sorry, Claude Scott (Letters, 7 October), but the Guardian report was correct. Battersea power station chimneys did emit smoke – from burning coal. It did not have cooling towers (which emit water vapour) as there was plenty of cooling water to be had from the Thames.
Rev Keith Burchell
Former power station engineer
• In your quick crossword (No 16,354, 6 October), the clue for 19 down was “Possessive pronoun”. The answer was “their”. Surely “their” is a possessive adjective, not a pronoun?
• Our maths master, while demonstrating a geometric proof, announced: “Just watch the board boys, while I run through it” (Letters, 7 October).
Dr Allan Dodds
• The answer to the question “Can pies grow?” (Letters, 6 October) is yes, they can, but only when their contents are putrefying.
Derek Leon Elton
Todmorden, West Yorkshire
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