The X-ray process was supervised by the McCrone Laboratory in Chicago, Illinois. Four x-radiographs were then assembled into one image by McCrone staff. (Fig. 4-1).
The x-radiograph reveals several unique features of the under drawing of Watching the Shot. It was Homer’s practice to draw in, using graphite, the main characters and landscape prior to adding pigment to the canvas. Watching the Shot is no exception. All of the soldiers, bridge, embankment, trees, etc. are shown to be part of the under drawing by the x-radiograph.
Primarily the painted image matches exactly the under drawing save only a few significant points. The huddle of Union soldiers in the water, forefront, have been grouped slightly tighter than their under drawing shows them. This was typical of Homer to adjust his drawing to accommodate spatial needs. Perhaps the most significant areas of the under drawing are what they do not reveal. The under drawing reveals that there is only one horse with a cavalry soldier on board, unlike the final painting that shows two horsemen. The flag bearer is part of the original under drawing while the cavalry man furthest right was added after the paint had dried on the canvas. Likewise, there is no general leading the troops in the under drawing as is seen next to the cavalry men in the water. The image of the general was also added after the pigments had dried. The x-radiograph cannot determine when these two images were added, only that they were not part of Homer’s original plan for the picture. This also conforms to Homer’s mannerisms at the time.