When the Capitol at Washington was threatened by the Confederate armies, it was still an unfinished structure, betraying its incompleteness to every beholder. This picture shows the derrick on the dome. It is a view of the east front of the building and was taken on July 11, 1863. Washington society had not been wholly free from occasional "war scares" since the withdrawal of most of the troops whose duty it had been to guard the city. Early's approach in July, 1864, found the Nation's capital entirely unprotected. Naturally there was a flutter throughout the peaceable groups of non-combatants that made up the population of Washington at that time, as well as in official circles. There were less than seventy thousand people living in the city in 1864, a large proportion of whom were in some way connected with the Government. [Illustration: PROTECTING LOCOMOTIVES FROM THE CONFEDERATE RAIDER COPYRIGHT, 1911, REVIEW OF REVIEWS CO.] The United States railroad photographer, Captain A. J. Russell, labeled this picture of 1864: "Engines stored in Washington to prevent their falling into Rebel hands in case of a raid on Alexandria." Here they are, almost under the shadow of the Capitol dome (which had just been completed). This was one of the precautions taken by the authorities at Washington, of which the general public knew little or nothing at the time. These photographs are only now revealing official secrets recorded fifty years ago. [Illustration: ONE OF WASHINGTON'S DEFENDERS COPYRIGHT, 1911, PATRIOT PUB. CO.] Heavy artillery like this was of comparatively little use in repulsing such an attack as Early might be expected to make. Not only were these guns hard to move to points of danger, but in the summer of '64 there were no trained artillerists to man them. Big as they were, they gave Early no occasion for alarm. [Illustration: ENTRANCE TO WASHINGTON FROM THE SOUTH--THE FAMOUS "CHAIN BRIDGE" COPYRIGHT, 1911, PATRIOT PUB. CO.] The sentry and vedette guarding the approach to Washington suggest one reason why Early did not make his approach to the capital from the Virginia side of the Potomac. A chain of more than twenty forts protected the roads to Long Bridge (shown below), and there was no way of marching troops into the city from the south, excepting over such exposed passages. Most of the troops left for the defense of the city were on the Virginia side. Therefore Early wisely picked out the northern outposts as the more vulnerable. Long Bridge was closely guarded at all times, like Chain Bridge and the other approaches, and at night the planks of its floor were removed. [Illustration: LONG BRIDGE AND THE CAPITOL ACROSS THE BROAD POTOMAC COPYRIGHT, 1911, REVIEW OF REVIEWS CO.] [Illustration] INSIDE FORT TOTTEN--THREE SHIFTING SCENES IN A BIG-GUN DRILL