the engineers were sent up stream to survey Bull Run for a ford. But a ford they were unable to find until Saturday, and the battle of Bull Run could not be fought before Sunday, July 21st. A fatal delay this proved to be. News of Tyler’s engagement at Blackburn’s Ford on the Thursday reached Johnston at Winchester, and that energetic officer, seeing that a general action must soon take place, slipped away from the aged General Patterson, and by a forced march through Ashby’s Gap of the Blue Ridge, he took train at Piedmont and marched most of his men into Beauregard’s camp on Saturday evening. One of his companies, indeed, did not arrive until Sunday afternoon, when by falling upon the Federals’ right, it gave the first intimation to McDowell that Johnston had given Patterson the slip. [Illustration: GENERAL SHERMAN.] A close, hot night preceded the eventful day. A mist, such as is so often seen on sultry nights in America, hung over the valley of Bull Run, blurring everything into a grey, indistinguishable mass, notwithstanding that the moon shone brightly. Shortly after midnight the Northern army bestirred itself to begin the work that lay before it. Tyler’s orders were to get away early from Centreville and to commence a hot attack on the stone bridge, as if it were McDowell’s intent to force his way across the stream at that point. As soon as Tyler and his men cleared the camp at Centreville, Hunter and Heintzelman were to march rapidly to the ford which the engineers had located, cross, and at the topmost speed consistent with a good formation advance upon Beauregard’s left, fall upon the rear of the defenders of the stone bridge and clear them away, and so allow Tyler to cross and join forces. McDowell hoped in this way not only to disorganise the Confederate arrangements, but also to prevent any chance of Johnston from Winchester joining Beauregard. He had no idea that Johnston had already effected the juncture. The Northern men, new to war, turned but drowsily from their sleep. It was night, and, unused to the necessity of quick and silent action, the men delayed and refused to be hurried. Consequently, before Tyler had got his men out of the way of Hunter, the hour for moving had long since passed. Tyler intended to attack the stone bridge at four in the morning. It was not until six that he fired his first gun. Hunter and Heintzelman were proportionately delayed. [Illustration: “TIME AFTER TIME THE ATTEMPT TO SCALE THE HEIGHT WAS MADE” (_p._ 99).]