According to the Library of Congress’s annotation, these photographs are probably two parts of a three-part panorama: the left and the center, or perhaps the center and the right. The third panel isn’t in the Library, however, and Photoshop’s automated merge function can’t bring the remaining two any closer to each other. They appear to have been taken from positions different enough to create a continuity error. From one image to the next, the curb’s line breaks to form an angle and the Baldwin Locomotive Works undergoes a change of perspective. Just when time almost stopped for an instant at the beginning of the twentieth century, the instant’s vanishing point was seen to move and blur as if it were alive after all.

So the visual forms that survive in the blur survive only as isolated colonies of the perceptible: the contextless cloud of steam, its whites and shadows sharply delineated but its purpose in its moment no longer knowable; the man with his tilted derby and rakish posture and shadow, never again to be nameable; the women in hats propelled along a route to the margin, blurred to unreadability above the moving words Wilbur’s American Milk Chocolate.

But at the right, unmoving, PHILA. It is only part of a word, but we seem to remember what the remainder once said of itself in the presence of a now vanished camera. From memory, memory recites DELPHIA. The sound is reassuring, because it seems stable. Tomorrow it will still be callable to mind and singable to completion once more.

But half of its harmony will sing in silent dark, because DELPHIA is a word in the dead language of the vanished panel 3. Looking down now at the two remaining panels, we experience panel 3 as if within its own aftermath: understanding it like a schoolbook remembered but no longer readable with a child’s eye. At their image’s vanishing point, the shadows of the man on the sidewalk and the women in the brand new motorbus and the mule just ahead of them on the road are to become equally unseeable because light will have moved forward past the brink of the image and disappeared into time.

Note added April 2, 2021: in his February 13, 2012 blogpost at https://www.shorpy.com/node/12391, Shorpy succeeds in merging the two images seamlessly and also provides a comment stream from which we learn, among other things, that the electric bus seen on North Broad Street dates the panorama to 1907 or 1908. Thanks, Kim Bridges, for calling the Shorpy link to my attention.