[46] Imagine what it must have meant even to get to the scene of action — with cumbersome tent and apparatus, and a couple of hundred glass plates whose breakage meant failure; over unspeakable back-country roads or no roads at all; with the continual chance of being picked off by some scouting sharpshooter or captured through some shift of the armies. The first sight of the queer-looking wagon caused amazement, speculation, derision. “What is it?” became so inevitable a greeting that to this day if one asks a group of soldiers about war-photographs, they will exclaim simultaneously, “Oh, yes, the ‘what-is-it’ wagon!” It became a familiar sight, yet the novelty of its awkward mystery never quite wore off. Having arrived, and having faced the real perils generally attendant upon reaching the scenes of keenest interest, our camera adventurer was but through the overture of his troubles. The most advanced photography of that day was the wet-plate method, by which the plates had to be coated in the dark (which meant in this case carrying everywhere a smothery, light-proof tent), exposed within five minutes, and developed within five minutes more! For the benefit of amateur members of the craft here are some notes from the veteran photographer, Mr. George G. Rockwood:
First, all the plain glass plates in various sizes, usually 8 x 10, had to be carefully cleaned and carried in dust-proof boxes. When ready for action, the plate was carefully coated with “collodion,” which carried in solution the “excitants” --bromide and iodide of potassium, or ammonia, or cadmium. Collodion is made by the solution of guncotton in about equal parts of sulphuric ether and 95° proof alcohol. The salts above mentioned are then added, making the collodion a vehicle for obtaining the sensitive surface on the glass plate. The coating of plates was a delicate operation even in the ordinary well-organized studio. After coating the plate with collodion and letting the ether and alcohol evaporate to just the right degree of “stickiness,” it was lowered carefully into a deep “bath holder” which contained a solution of nitrate of silver about 60° for quick field-work. This operation created the sensitive condition of the plate, and had to be done in total darkness except a subdued yellow light. When properly coated (from three to five minutes) the plate was put into a “slide” or “holder” and exposed to the action of the light in tile camera. When exposed, it was returned to the dark-room and developed.
