After its half-mile journey between the great, square sordid mountains of stone and steel that lie to the north of Fourteenth Street, Fifth Avenue emerges into the sunshine of Madison Square. There it draws in deep breaths of pure ozone before resuming its way as a canyon at Twenty-sixth Street. Reverting to the past, from the Square to Thirty-first Street, the lane runs through what was the Caspar Samler farm. North of that were the twenty acres that John Thompson bought in 1799 for four hundred and eighty-two pounds and ten shillings. A little later, a more familiar name appeared on the maps. In 1827 the Astor hand reached up to this then remote section, William B. Astor purchasing a half-interest, including Fifth Avenue from Thirty-second to Thirty-fifth, for twenty thousand five hundred dollars. While other real-estate investors who considered themselves astute were planning for the future by gobbling up stretches of land along the shore of the East River the Astors were buying across what was primitively known as the backbone of the island. The sharp rise to what was the old summit and to the modified hill of the present does not begin until Thirty-third Street is reached. But there is perceptible a grade of a kind as soon as the Avenue leaves the northern line of the Square. Today it is a slope in transition. Here and there the change has been wrought. A modern structure reaches superciliously skyward. Beside it and below it the buildings of yesterday give the impression of feeling acutely conscious of their impending doom. They know. Their race is almost run. Tomorrow the old bricks will be tumbled down, the chutes will roar with their passing, and the air will be shrill with the steam drills and riveters ushering into the world the young giants that will take their places. At the northeast corner of Twenty-sixth Street, where the Avenue touches the Square, there is a vast edifice of surpassing ugliness. It is the Brunswick Building, on the site of the old Brunswick Hotel, once famous as the headquarters of the Coaching Club. At one end the principal establishment of one of those firms that have given the term "grocer" a new meaning, at the other, a great book-shop of international reputation, and between, a booking office where the pictures and maps in the show windows stir the passer-by to disquieting dreams on streams of Canada and Maine in the summer, and of semi-tropical verdure in the winter.