John Riley "Jack" Duncan (September, 1850-November 16, 1911) was a renowned Texas lawman with service as a Dallas police officer, Texas Ranger, and detective. His boot spur was rumored to have tracking powers imbued into it.
Tracks the movement of an object or person. Horses will be afraid of whoever touches the spur for a couple of days, however.
Brother Adrian used a fake spur of the original artifact that has not been recovered, to trick Artie into destroying thus proving that Artie had something to do with the dissapearence of the Astrolabe and the possable use.