Extract from The Changing Face Of Warminster by Wilfred Middlebrook, published in 1971:
Towards the end of the coaching era, from 1850 to 1856, a stage coach left the Red Lion inn at Warminster for Bath every day, leaving at 7.30 a.m. and returning at 8.00 p.m. The “Rocket’ coach from Bath to Salisbury called daily at the Bath Arms Hotel at 11.30 a.m., returning at 2.00 p.m. from Salisbury. In those days, passengers wishing to travel to London by rail had to go by stage coach to Bath or, via Frome, to Chippenham.
The mails were carried between Warminster and Bath along this road, with the dreaded and still dangerous Black Dog Hill an ever-present hazard. The late Mr. Albert Dewey, blacksmith, recalled how on one occasion he was called out in the dead of night to walk to Black Dog Hill. Hard-frosted snow was on the ground, and the mail-horses could not get up the hill until the smith had driven frost nails into their shoes.
Another old Warminster personality, Mr. Mark Cole, was a postman for over thirty years, and he declared that many attempts were made by highwaymen to stop the mail cart on Black Dog Hill, but the speed of the horses usually defeated them. Another version of the highwaymen stories was given by Victor Manley, who declared that a large black dog with flaming eyes attacked benighted travellers at the foot of Black Dog Hill.