The Ames family home is described, by Deborah, as being on the Great Western line out of London. Later Fortescue is misidentified as the dog clipper from Faversham. But Faversham is on the other side of London, on the north coast of Kent. (This town being on the South Eastern and Chatham Railway, not the Great Western). It seems highly unlikely that the family would employ a dog clipper from so far afield.
Deborah tells Fortescue that Lord Ames' country seat is in Moretonhampstead, "on the Great Western line, two stops before Chippenham". Moretonhampstead was indeed on the Great Western Railway, but at the end of a now closed branch line in Devon, over a hundred miles west of Chippenham, more than 200 miles by train from London - and a very long day's journey from Faversham.