The geologist and his hammer should be inseparable. There are many patterns of this useful instrument, but the most generally serviceable, perhaps, has a head of well-tempered (not too hard) steel, about five or six inches in length, and having a face about one inch square at the one end, and a horizontal chisel-edge at the other. The shaft should be of ash, and about eighteen inches in length, marked off into spaces of three inches each so that it can be used as a measure.
W. J. Harrison, A Textbook of Geology, 1897
Hammer For Scale traces individual instances of a common field instrument as found in the U.S. Geological Survey Web Archives. These images, made over the course of a century portray rock hammers photographed against varying features of the landscape. The compilation tackles the peculiarities of a delineating vision, which borrows the formal qualities of an emblematic tool in configuring a standard placeholder to negotiate with nature.