Suppose you suddenly dropped through a hole in time and found yourself in the Pittsburgh of 1815. How would you find your way? What was the population? What were the street names then? Where would you find a watch, or a suit of clothes, or wholesale German imports? Was there a library? How would you post a letter?

In case that happens remember this name: James M. Riddle, on the south side of 3d, between Market and Wood streets, and nearly opposite the Farmers’ and Mechanics’ Bank. Mr. Riddle has published a complete directory of the booming Borough of Pittsburgh, and no visitor from the future should be without it.

You will notice that there are no addresses. Though it had already grown to be one of the ten largest cities in the country, Pittsburgh had not yet numbered its houses and buildings. Instead, an address would be given as “S side of Virgin alley between Wood and Smithfield,” and if you wanted anything more specific, you would probably have to ask someone on the street.