THE heaviest battery of artillery ever mounted in the world, up to 1862, was before Yorktown when the Union army was maneuvering to enter Richmond from the south. The intention was to shell the Confederates out of a strongly intrenched position by overwhelming fire. This photograph was taken inside of the fortification that threatened to annihilate an entire army. In it were huge demons of death--that were hitherto unknown in warfare--capable of throwing 900 pounds of iron at one broadside into the lines of the enemy. There were five 100-pounder and two 200-pounder Parrot rifled cannon. The topography of the country would not admit of engagements with unfortified lines. The Confederates concentrated their forces in the woods. The Union commanders at first despised picks and shovels. They insisted that all defenses except those naturally available were beneath a soldier's dignity. The battles of the East and West were being fought on open ground. The campaign against Richmond, however, proved the necessity of defenses to protect the lines from unexpected attacks from the hidden enemy. The Confederates became uneasy over this shift of fighting front and the magnitude of the preparations at Yorktown so astounded them that they abandoned the position. On May third the great battery threw a charge into the Confederate stronghold. It was intended to open the bombardment on the following morning, but at dawn it was found that the Confederates had evacuated. The heavy artillery was known as Battery No. 1, and manned by Company B, First Connecticut Heavy Artillery. It became a matter of discussion throughout the world. Military attachés from many foreign powers visited the breastworks to report the situation to their governments. [Illustration: PHOTOGRAPH TAKEN BEHIND THE BREASTWORKS AT YORKTOWN, VA., IN 1862]