ENGINEERING. 385 



IMPROVEMENT ON THE UPPER MISSISSIPPI. 



The last year witnessed, also, the completion of the canal 

 constructed by government engineers with the object of 

 overcoming the obstruction to navigation caused by the Des 

 Moines rapids in the Mississippi at Keokuk, la. The follow- 

 ing account of the character and importance of this work 

 may be found of interest. The canal extends along the Iowa 

 shore from Keokuk to Nashville a distance of seven and six- 

 tenths miles. It is three hundred feet wide in embankment 

 and two hundred and fifty feet wide in excavation; mini- 

 mum depth of water, five feet; maximum depth, eight feet, 

 which is sufficient to float the largest steamers that ply the 

 Upper Mississippi. Entire fall in length of canal, 1875 feet. 

 There are two lift-locks and one guard-lock, each three hun- 

 dred and fifty feet long and eighty feet wide on top, solidly 

 built of cut-stone masonry. Sluices of ample capacity to 

 control the surplus water carried into the canal during the 

 flood season are built around the locks. The cost of the 

 work thus far has been $4,281,000, and $100,000 will still be 

 required to finish it. The Engineering News affirms that 

 this work is of incalculable importance to the navigation of 

 the Mississippi River, as it removes the only obstruction that 

 remained between New Orleans and St. Paul. 



THE MADEIRA AND MAMORE RAILWAY. 



In future commercial possibilities, the work of the building 

 of this railroad (a contract for which was last year given by 

 the agent of the Bolivian Government to certain American 

 capitalists) is doubtless the most important enterprise that 

 has lately been undertaken. The successful accomplishment 

 of this project will have for its practical result the opening 

 of a region of South America vast in extent, and of vast 

 though undeveloped mineral and agricultural resources, but 

 which, by reason of almost insurmountable natural obstacles, 

 has been heretofore practically isolated from commercial in- 

 tercourse with the world. The object of the proposed im- 

 provements, which are on a scale of great magnitude, is, by 

 the construction of a line of railway, to bridge a gap of 

 about one hundred and eighty miles, in which the existence 

 of numerous falls and rapids opposes at present a complete 



R 



