The following photos are credited to R. O. Quesnel ("Quesnal" in the book) in the 1914 edition of Williams' "Yosemite and Its High Sierra":

"Climbing the Half Dome. A climber making his way up across the projecting layers of granite. This feat was first performed in 1875 by George Anderson who drilled holes and set eye-bolts in the northeast slope, the only practicable route." (p. 86)
"The ascent is now made by occasional adventurers, aided by Anderson's spikes and a rope." (p. 86)		"Overhang at Summit of Half Dome, nearly a mile above the Valley floor and Tenaya Canyon. El Capitan is seen in the distance." (p. 87)

Note: The black line down the slope, on the second photo, could be a rope.

Royal Quesnel was an electrician (and a climber), living in Yosemite Valley from about 1912 to about 1915.

Here is an interesting comparison between Royal's photo of Half Dome's northeast slope back in 1912, and a photo of the slope taken in 2006.