A footnote to the steam locomotive Mallard’s record-breaking run

The note correcting the quick crossword clue about the world record speed for a steam locomotive (Corrections and clarifications, 5 September) raises an interesting point.According to an article by David Andrews in the August 2018 edition of the authoritative railway magazine Back Track, Mallard touched 126 mph for just one second, and therefore the substantive speed is actually 125 mph, as the LNER originally claimed.