The Glass Block.
Built in 1884, it was the height of style: clean outside and within, brightly lit by an interior court, with an observation dome open to the adventurous shopper. After years of looking at this picture - not continuously, of course - I wonder now if the left-hand side was built after the corner portion. In any case, it was an impressive addition to the city, and certainly put its neighbors to shame. Especially the one on the far right, which looks like something drawn on canvas for one of Edison's early films.