"No—oh, well I don't need him right away."
"And nothing was taken except some old photographs?" asked Craig, looking intently at Carton's face.
"That is all I can find missing," he returned frankly.
Kennedy's examination of the looted study was minute, taking in the window through which the thief had apparently entered, the cabinet he had forced, and the situation in general. Finally he set up his camera with most particular care and took several flashlight pictures of the window, the cabinet, the doors—including the study—from every angle. Outside he examined the extension and back of the house carefully, noting possible ways of getting from the side street across the fences into the Carton yard.
With Carton we returned to Craig's splendidly equipped photographic studio and while Carton and I made the best of our time by discussing various phases of the case, Kennedy employed the interval in developing his plates.
He had ten or a dozen prints, all of exactly the same size, mounted on stiff cardboard in a space with scales and figures on all four margins. Carton and I puzzled over them.
"Those are metric photographs, such as Bertillon of Paris used to take," Craig explained. "By means of the scales and tables and other methods that have been worked out, we can determine from those pictures distances and many other things almost as well as if we were on the spot ourselves. Bertillon cleared up many crimes with this help, such as the mystery of the shooting in the Hotel Quai d'Orsay and other cases. The metric photograph, I believe, will in time rank with other devices in the study of crime."
He was going over the photographs carefully.
"For instance," he continued, "in order to solve the riddle of a crime, the detective's first task is to study the scene topographically. Plans and elevations of a room or house are made. The position of each object is painstakingly noted. In addition, the all-seeing eye of the camera is called into requisition. The plundered room is photographed, as in this case. I might have done it by placing a foot rule on a table and taking that in the picture. But a more scientific and accurate method has been devised by Bertillon. His camera lens is always used at a fixed height from the ground and forms its image on the plate at an exact focus. The print made from the negative is mounted on a card in a space of definite size, along the edges of which a metric scale is printed. In the way he has worked it out, the distance between any two points in the picture can be determined. With a topographical plan and a metric photograph one can study a crime, as a general studies the map of a strange country. There were several peculiar things that I observed at your house, Carton, and I have here an indelible record of the scene of the crime. Preserved in this way, it cannot be questioned. You are sure that the only thing missing is the photographs?"
Carton nodded, "I never keep anything valuable lying around."