Pass on to the box-window. There you read the history of men in trade and commerce. There you have a compendium of that wonderful thing known as and called ‘Change. There you will observe the various and peculiar characteristics of men as they eagerly clutch their letters and rush away. Watch their actions, and you will find that a line or two in a letter convulses the market, and for a while there is a commotion on ’Change. Watch the politician: by his looks you can read the secret of his heart. If you follow his footsteps and read the name of the publication-office into which he plunges, the chief editorial next day tells its contents. Perhaps it will read, “Reliable Intelligence from Richmond. The Rebel Army well supplied with Ammunition. Probable Recognition by England, &c.” Or, perhaps, if the publication-office should be on Fourth or Third Street, it may read, “Glorious News from Grant’s Army, &c.” There is another portion of a post-office which adds another page to its romantic history; and that is the “Carriers’ Department.” Many a sad tale has the carrier to tell,—many a strange incident connected with his “constant round.” A glance into this room shows you a number of men busily engaged in assorting or “blocking” the letters on their route. These they receive in bulk from the distributor, which are passed to them from a smaller room through a series of pigeon-holes. And here we have a most remarkable illustration of what the human mind is capable of accomplishing. Let us explain. In 1854 the corporate limits of the city of Philadelphia were made coextensive with those of the county, covering an area of one hundred and twenty square miles, and placing twenty-one towns and villages under the guardianship of one Mayor and City Councils. In nearly all of these there were separate post-offices. The bringing of all these rural districts under one general postal head was one of the first suggestions that Mr. C. A. Walborn made to the department shortly after he became postmaster of this city. Postmaster-General Blair entered fully into his views upon this subject, and thus the whole rural district embracing the area named above is under one general postal head. Mr. Walborn established station-offices, engaged carriers; and letters are distributed within an area of over one hundred miles, with as much ease and facility as they were in the limits of the old city proper.