The close of the war was signalized bj his marriage, May 23d, 1865, 

 to Miss Mary Gordon Gairdner, of Augusta, Ga., and by his removal to 

 Baltimore, where he resumed the practice of his profession as an engineer 

 of bridges. In 1866 he associated himself with Messrs. Benjamin and 

 Charles Latrobe as partners in the engineering firm of Smith, Latrobe & 

 Co., which in 1869 became the "Baltimore Bridge Co.," an organization 

 which continued until 1S77 with Mr. Smith as Mr. President and Chief 

 Engineer. 



In 1868 Mr. Smith left Baltimore and came with his family to St. 

 Charles, Mo., to take charge as Chief Engineer of the bridge at that point 

 over the Missouri river. In 1871, upon the completion of the St. Charles 

 bridge, he changed his residence to St. Louis, where he remained until 

 his death, which took place December 19th, 1886, after an illness of nearly 

 two years. 



Few engineers of his time have done as much work as Mr Smith. His 

 bridges are numbered by hundreds, and include four over the Mississippi, 

 one over the Missouri, and one over the St. Lawrence. Some of them 

 mark eras in the history of this department of engineering; for he had 

 both the ability and the courage to leave precedent behind him, and some 

 of the methods of construction which he introduced have permanently 

 increased the resources of his profession. Amongst these may be noted 

 the use of iron trestle-work, which he was the first to employ on any im- 

 portant scale by building, in 1S68 and 1869, nine structures of this kind, 

 ranging in height from 50 to 135 ft. 



But his most important professional work wr.s without doubt his prac- 

 tical demonstration of the uses and value of the cantilever, in the employ- 

 ment of which he was, in this country at least, the pioneer. His first use 

 of the cantilever was in 1869, when he erected on this method, without 

 scaffolding, a 3CO-ft. draw-span over Salt river in Kentucky. His next 

 work of this kind was the bridge, built in 1876-7, on the line of the Cincin- 

 nati Southern Railroad over the Kentucky river. This consists of 3 spars 

 of 375 ft., each with a height of rail above the bed of the river of 276 ft. 

 This great height as well as the danger from freshets, which in this river 

 are very frequent and severe, made the ordinary methods of erection very 

 expensive as well as very hazardous. 



Mr. Smith resorted to the method which he had already used at Salt 

 river, which has since been used with such marked success at Niagara, 

 namely, that of building the bridge out of piece by piece without the aid 

 of scaffolding; afterwards, by severing the bottom chords of the side- 

 spans, they were converted permanently into true cantilevers. This was 

 one of the boldest and most successful of Mr. Smith's works, and, if he 

 had done nothing else, would mark him as one of the first engineers of 

 his time. 



Still another and hardly less interesting example of this class of struc- 

 tures is the bridge over the Mississippi river, between Minneapolis and 

 St. Paul, near the falls of Minnehaha; whilst the last, and in some re- 

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