Ronald John McNeill, 1911 Encyclopædia Britannica, Volume 8… (1911)
“ The driver should therefore always just “feel his horse’s mouth” as lightly as possible; he then has the animal well under control in readiness for every emergency, while avoiding such a pull on the mouth as would cause a high-spirited horse to chafe and fret. Well-broken carriage horses should always be willing to run into their bits, and those that draw back when lightly held in hand should be kept up to the bit with the whip. ”
