Natural gas is added to coal and coke in the region beyond Greensburg, and the villages display flaring gas torches at night for street lamps. The whole country, north, south and west, is a network of railways and a maze of mines, having long rows of burning coke ovens lighting the sky with their lurid glare. Here are mined the Westmoreland gas coals. The valley of the Monongahela River, coming up from West Virginia, approaches from the southward, a great highway for coal boats out to the Ohio and the West, also receiving a large coal tribute from its branch, the Youghiogheny, flowing by crooked course through Fayette County. Alongside the Monongahela is the great Edgar Thomson Steel Works, one of the chief establishments of the Carnegie Steel Company, making railway rails. Here is the famous Colonial battlefield of Western Pennsylvania, made immortal by General Braddock's defeat in July, 1755. This region was then a thick forest, through which an Indian trail coming over the Monongahela led to the junction of the two rivers forming the Ohio, where the French had established their stockade and trading post of Fort Duquesne. Braddock came into this region from beyond the mountains, his object being the capture of the fort. His defeat, a great event in our Colonial history, was due to his ignorance of the methods of Indian fighting and his refusal to listen to those who understood it; but he paid the penalty with his life, being shot, as was believed at the time, by one of his own men, after having had five horses shot under him. It was in rallying the defeated remnant that Washington, the senior surviving officer, won his first military laurels. Braddock crossed the river and was caught in an ambuscade, eight hundred and fifty French and Indians surprising and defeating his force of about twenty-five hundred British regulars and Virginia Provincial troops, the loss being nearly eight hundred. Washington led the remnant back to Virginia, carrying Braddock about forty miles on the retreat, when he died. He was buried at night in the centre of the road, Washington reading the Episcopal burial service by torchlight, and the defeated army marched over the grave to conceal its location from the enemy. A handsome monument is erected on the battlefield at Braddock's. And thus, through iron mills and coal mines, amid smoke and busy industry, the Pennsylvania Railroad enters Pittsburg, the "Iron City." THE GREAT IRON CITY.