Capt. John Ericsson was a Swedish engineer, residing in this country, who had won a name for himself by inventing the screw-propeller as a means of propulsion for steamships. He and a Connecticut capitalist, C. S. Bushnell by name, had ever since the opening of the war been trying to induce the Government to build some iron-clads after a pattern designed by Ericsson, and which afterwards became known as the "monitor" pattern. Their labors at Washington met with little success. After a long explanation of the plan before the wise authorities of the Naval Board, Capt. Ericsson was calmly dismissed with the remark, "It resembles nothing in the heavens above, or the earth beneath, or the waters under the earth. You can take it home, and worship it without violating any Commandment." Finally, however, leave was obtained to build a monitor for the Government, provided the builders would take all financial risks in case it proved a failure. So, with this grudging permission, the work of building the warship that was destined to save the Federal navy was begun. Work was prosecuted night and day, and in one hundred days the vessel was ready for launching. Great was the discussion over her. Distinguished engineers predicted that she would never float; and many attended the launch expecting to see the vessel plunge from the ways to the bottom of the river, like a turtle from a log. So general was this opinion, that boats were in readiness to rescue her passengers if she went down. But Capt. Ericsson's plans were well laid. The great vessel glided with a graceful dip into the river, and floated at her cables buoyantly. She was a strange-looking craft. All that was to be seen of her above water was a low deck about a foot above the water, bearing in the centre a large round iron turret pierced with two great portholes. Besides the turret, the smooth surface of the deck was broken by two other elevations,--a small iron pilot-house forward, made of iron plates about ten inches thick, and with iron gratings in front; aft of the turret was a low smokestack. Beneath the water-line this vessel had some strange features. The upper part of her hull, forming the deck, projected beyond her hull proper about four feet on every side. This projection was known as the "overhang," and was designed as a protection against rams. It was made of white oak and iron, and was impenetrable by any cannon of that day; although now, when steel rifled cannon are built that will send a ball through twenty inches of wrought iron, the original "Monitor" would be a very weak vessel.