“More commonly known as blueprint, cyanotype ranks as the third photo process to be discovered, after the daguerreotype and the talbotype. Invented in 1842 by Sir John Frederick Herschel, the cyanotype is the result of iron salts that leave behind a characteristic blue deposit when rinsed away by water after exposure to light. The relative ease, low cost and practicality of this running-water technique accounted, in part, for its popularity among artists, architects and engineers. Poulet took advantage of this, making contact prints from collodion-glass negatives as he moved along with the construction of the railroad. With its informative essays and full annotation, this book is a fine appreciation of Poulet's achievement.
Poulet's blue chronicle admirably sets its scenes, from the Argentinean ports where railroad supplies arrive to the interior of the rugged country. His images capture crisp details of the railroad trestles and ironwork that begin the industrial transformation, and many of his shots view the railway construction from a distance, over swampy, scrubby expanses. These photos of an undeveloped terrain in the throes of modern change are vital documents, memorializing not only the engineering spectacle but also the humanity behind it, as teams of workers are caught in the act of hauling, hammering, and subduing the rough clay of Argentina.”