proceedings of the polytechnic association. 483 

 Delano's Stove. 



Mr. Frisbiethen exhibited a model of Delano's improved coal-burning 

 etove, alluded to by the Chairman, which he briefly explained, fuller details 

 .being reserved for the next meeting, as the hour devoted to miscellaneous 

 business had expired. 



Iron-clad Vessels of War. 



The subject of iron-clad vessels was then taken up, when the Chairman 

 introduced Commodore W. D. Porter, of the gunboat Essex, which lately 

 achieved a brilliant success on the Mississippi river. 



The Commodore said: The subject of iron-clads is one that is now engag- 

 ing the serious attention of the civilized world. The gunboat Essex, to 

 which I was attached, you are doubtless aware was coated on certain parts 

 with sheets of India rubber, of a peculiar manufacture, one inch thick, and 

 over this was placed plates of iron one inch thick. We have been in some 

 fierce contests, which, in my opinion, proves that the use of an elastic sub- 

 stance between the iron and the wood, will largely increase the power to 

 resist penetration, by enlarging the base of resistance wherever struck, by 

 diffusing the force of the blow over a greater surface. In the action of the 

 Essex, when she destroyed the rebel iron-clad Arkansas, she had to pass 

 the batteries' at Vicksburg, one of which mounted eighty guns. This bat- 

 tery is built where the river is very narrow, and the Essex was the first of 

 the iron-clads that had to be placed under such a fire. The other miserable 

 machines, called gunboats, were a disgrace to the country, as in action 

 their wooden sides would be penetrated through and through. The Essex 

 passed through this fire without serious injury, and was the first to gain a 

 victory — a victory which resulted in destroying the most formidable iron- 

 clad that the rebels had constructed. In doing this we had to pass by 

 several small forts mounted with heavy guns. The Arkansas threw forty- 

 eight heavy shots into us, notwithstanding which we delivered our fire, and 

 drove in her casemates, killing thirteen of her men. In all her engage- 

 ments the Essex had but one man killed. After I left her she was pene- 

 trated by a 120 pound ball, which passed clear througli her. It of course 

 broke the India rubber, but after the ball went through the India rubber 

 closed up again to its original form. The Essex cost from first to last 

 $186,000, and the Benton $286,000; this last named boat was covered with 

 plain iron, and she was completelj'' destroj'cd. In the case of the Merrimac 

 and the first Monitor, the Merrimac got away from her, but with the Essex 

 and the Arkansas, the latter was destroyed. The Commodore concluded 

 by illustrating on the blackboard the armor of the Essex. 



Mr. J. L. Jones gave the following 



HISTORY OF THE ESSEX. 



The Essex was originally a common ferryboat on the Mississippi river, 

 and was originally called the New Era. She ran between St. Louis and 

 Illinois town. While thus employed, a fire occurred on board, and her 

 cabin and wheels were burned, and nothing left but the hull and main deck, 

 which was badly charred. Her owners repaired her, and in the early part 

 of 1861 she was purchased by government, and prepared for a cruise up 



