Leatherette Edition Page 61 6th paragraph reads "and not a boot-heel, but a shoe" and then on Page 62 Last long paragraph reads "near the bank where from under the sand an edge of a boot showed" The person being tracked has changed his footwear in about a page of writing.
Les The location of your mailbox shows you how far away from your house you can go in a robe, before you start looking like a mental patient.