548 THE POPULAR SCIENCE MONTHLY. 



of seven ironclad gunboats. These were designed by Mr. Eads, and 

 he undertook to build them in sixty-five days — a short enough time 

 under the best of circumstances ; but business was then disorganized 

 and all industrial enterprises in a chaotic condition. The materials 

 with which the work was to be done had to be manufactured. Yet 

 these seven heavily-plated vessels of about six hundred tons each were 

 all finished according to contract, and another one still larger, a snag- 

 boat, was by alterations and heavy plating made ready with the others 

 for their armament. " Thus one individual put into construction and 

 pushed to completion within a hundred days a powerful squadron of 

 eight steamers aggregating five thousand tons, capable of steaming 

 at nine knots per hour, large, heavily armed, fully equipped, and all 

 ready for their armament of one hundred and seven large guns. The 

 fact that such a work was done is nobler praise than any that can be 

 bestowed by words." * 



In 18G2 Mr. Eads was commissioned to build six more armored 

 iron gunboats, four of which were much lai'ger than any of the eight 

 preceding ones. These were likewise after his own designs, four of 

 them having two turrets each and the smaller ones one turret each. 

 These turrets were a modification of the Ericsson turrets, the Gov- 

 ernment insisting upon these being placed upon them. He Avas, how- 

 ever, permitted to place one turret on each of two of these large 

 gunboats, after his own design, and costing about thirty-five thousand 

 dollars each, but on the written condition that they should be re- 

 placed by Ericsson turrets if they were not found satisfactory. The 

 guns in these two turrets were worked by steam, and this was the first 

 time in the history of artillery-practice when heavy guns were ma- 

 nipulated wholly by steam. These vessels all proved to be of lighter 

 draught than had been stipulated, so that it was possible to add from 

 half to three quarters of an inch to their armor ; and three of them 

 exceeded very considerably the contract speed. While these fourteen 

 ironclads were under way, Mr. Eads also had the construction of four 

 heavy mortar-boats and seven tin-clad or musket-proof boats. The 

 kind of ironclads that Mr. Eads designed and constructed and the 

 kind of work they did are recorded in the history of Grant and Ilal- 

 leck's campaigns, and of Farragut's capture of Mobile. 



In the construction of a steel-arch bridge at St. Louis, on which he 

 was engaged from 1867 to 18T4, Mr. Eads had to deal with problems 

 which had not before confronted an engineer. The central arch of 

 this structure has a clear span of five hundred and twenty feet, and is 

 pronounced, by the "British Encyclopaedia," the finest specimen of 

 metal-arch construction in the world. The side arches are five hun- 

 dred and two feet each in span. All of the piers, in consequence of 

 the shifting deposits beneath the river-bed, were sunk clear through 

 to the bed-rock. This required them to be sunk much deeper than 

 * Boj-nton's " History of the Navy during the Rebellion." 



