Pittsburgh and New Orleans--both of vast commercial importance--are connected by one of the greatest water highways in the world. Never were two cities more unlike. New Orleans, near the mouth of the Mississippi, with its French and its Southern population, might be termed the Paris of our country--this gay, fashionable town, with its fine opera houses, its noted restaurants, and its brilliant Mardi Gras pageants. Pittsburgh, on the other hand, at the head of the Ohio River, in the heart of a famous coal-and-iron region, is well named the "workshop of the world." Many years ago, when the governor of Virginia sent George Washington to drive the French from the Ohio valley, there stood, where the Allegheny and Monongahela rivers unite to form the Ohio River, a small fort which the French called Fort Duquesne. This fort was captured in 1758 by the British and renamed Fort Pitt, in honor of England's great statesman, William Pitt. To-day the place is known as Pittsburgh, and is the center of the most extensive iron works in the United States. At first the little settlement was important as a break in transportation, for here cargoes were changed from the lighter boats used on the Allegheny and Monongahela rivers to the heavier barges on the broad Ohio. Even then Pittsburgh was recognized as a gateway of the West. Gradually the settlement became a trading center, which soon developed into a big, busy, manufacturing city. Now Pittsburgh has a population of over half a million and is the eighth city in size in the Union. [Illustration: FORT DUQUESNE] In her countless factories, her mammoth steel mills, and her huge foundries, she uses the products of the rich surrounding country as well as an enormous amount of iron ore from the Lake Superior mines. Although western Pennsylvania too furnishes iron ore, its chief contribution to Pittsburgh is a vast amount of coal, which the city in turn supplies to the world. Pittsburgh leads the world in the manufacture of steel and iron, glassware (including plate and window glass), armor plate, steel cars, air brakes, iron and steel pipe, tin plate, fire brick, coke, sheet steel, white lead, cork wares, electrical machinery, and pickles. [Illustration: BLOCKHOUSE IN FORT DUQUESNE] To carry on these important industries, Pittsburgh, the city of McKeesport, the boroughs of Homestead and Braddock, and many other places,--all together known as the Pittsburgh district,--have more than 5000 manufacturing plants and employ over 350,000 people. The amount paid the laborers in these factories in prosperous times is over $1,000,000 a day. [Illustration: THE PITTSBURGH DISTRICT] [Illustration: FILLING MOLDS WITH MOLTEN METAL]