This 1858 print is an advertisement for the combined letter box and lamp post patented in that year by iron importer Albert Potts. It shows a woman wearing a bonnet and coat placing a letter in the box, which is marked with abbreviated words indicating that it belongs to the Philadelphia post office of the U.S. mail service. In the shadowy background, a newsboy runs by, a couple approaches on the sidewalk, and the office of Potts & Roberts (Albert Potts and A.C. Roberts), located at the northeast corner of Third and Willow Streets, is visible. The street names are posted on the office building and neighboring buildings are partially in view. The wording at the bottom of the advertisement explains that the main object of the invention “is to afford increased postal facilities for the deposit of Mailable matter by attaching the boxes to Lamp Posts at short intervals; the convenience of the light from the lamp is a desideratum the advantages of which are evident.”