Picture shows Anderson's eyebolt from 1877, found on Mount Starr King.
See a full-size version
at the Yosemite Climbing Association site.
Anderson probably used the same type of eyebolts on Half Dome.
The photo shows Anderson's spike found on Half Dome.
See a full-size version
at the Yosemite Climbing Association site.
Links:
Chronicles of Early Ascents of Half Dome
Half Dome Day Hike, 2006