Apprenticed in the Washington, D.C., portrait studio of Mathew Brady and matured and tested under the most trying conditions as a field photographer during the Civil War, Timothy O’Sullivan was perfectly suited to participate in the postwar government-sponsored expeditions in the American West, including the 1871 and 1873 seasons of George Wheeler’s survey of territory west of the 100th meridian. At Inscription Rock, New Mexico, a towering formation with a reliable watering hole at its base, Wheeler’s team stopped at a spot that for centuries had attracted travelers, many of whom left marks carved on the natural stone wall. Among those earlier visitors was Don Joseph de Payba Basconzelos, who paid for the return of expelled council (cabildo) members to Santa Fe from Mexico City after a three-and-a-half-year banishment by New Mexico’s governor. The translation of his writing is “The Ensign Don Joseph de Payba Basconzelos passed through here on the 18th of February, 1726, the year he returned, at his own expense, the members of the cabildo to the kingdom.”

Like many an explorer or archaeologist, O’Sullivan included a yardstick in his frame to provide scale, but here it seems to take on a central role, as if to suggest the power of positivism (and its ideal recording tool, photography) to measure and therefore comprehend physical space, the passage of time, and man’s place in the natural world. So inverted are the photograph’s nominal subject and the photographer’s intervention that O’Sullivan’s picture might well be mistaken for a work of 1960s or 1970s conceptual art.