/ proceedings of the polytechnic association. 503 



The Dunderberg. 



. Dr. J. B. Rich. — Through the kindness of Mr. Webb I visited the famous 

 ram "Dunderberg," now building at his yard, and there can be no doubt 

 •but when completed she will be a most formidable vesseh Her extreme 

 length is 380 feet; breadth, 70 feet; depth of hold, 23 feet. She has two 

 ■turrets, 11 inches thick, each having two 15-inch guns, and eight 11-inch 

 guns in casemates. Her tonnage is 7,000 tons. The length of the ram is 

 60 feet. She has two cylinders of 100 inches diameter, and will be 6,000 

 horse power. Her screw is of 32 feet pitch, and will be capable of a speed 

 of 15 miles an hour. Thirty-one feet from top of casemates to keel. The 

 braces are 14 inches wide and eight inches thick. The hull is divided into 

 several water-tight compartments. The casemates are built at an angle 

 of 60 degrees, and in order for a ball to go through them it will have first 

 to pass through several feet of coal, as the casemates are lined on each 

 side by the coal bunkers. 



The Monitors. 



• Mr. B. S. Osbon. — A very successful arrangement in the monitor style 

 of gunboats is that in the overhang of the vessel there are placed anchor 

 wells, in which anchors are hung, so that wherever it is desirable to take 

 ia position, these anchors are dropped without being seen by the enemy. 

 The monitors were built with a view to harbor defence only, but the gov- 

 ernment sent them down south to batter down forts, some of them sand 

 forts. At Charleston they have been struck over 1,000 times, and still 

 there has been no material injury inflicted on them, and I may say they 

 look like a pair of prize fighters faces, showing evidence of some rough 

 handling, but nothing more. There has not been a single man killed in a 

 monitor yet. It is a matter of no small pride to know that we have revo- 

 lutionized the mode of modern warfare, and that we are building to-day an 

 iron ship that will surprise the world. As a vessel replete, with all the 

 modern appearances for defence and ofience, I think the iron ship Dictator 

 stands first. And the reason why England and France did not interfere in 

 our affairs long before this, was the failure of her iron-clad ships whenever 

 during their trial trips they went beyond smooth water. Our monitors 

 being of light draft can be managed in shallow and. narrow channels, and 

 so maneuvered as to get a large ship where it cannot turn and then go at 

 her, and if advisable our monitors can get away easily. I have no doubt 

 that the Dictator would go right through the English Warrior. We can 

 imagine what it would be for a ship to be struck on the side with an iron 

 ram twenty feet long. We are also making great improvements in guns. 

 I have seen a gun that can be fired in a seaway with perfect safety, and 

 fire and recoil and go back to its right position. The greatest tr(juble at 

 sea is with the large guns, the 11-iuch, which cannot be kept in their places, 

 but go rolling about the vessel. I have seen them tied up with every rope 

 to be had on board, and I have even timed them, and found them to roll 

 24 times in a minute. We had a boat on the Mississippi called the Miona, 

 which we named the " Miasma," for she would not go in any way. Vessels 

 like these have been a source of annoyance in all our expeditions. If we 

 look at the lists of prizes captured, we will find that nlost of them were 



