680 Transactions of the American Institute. 



Paris to La Yanne is over 135 miles; and as there were hills, valleys, 

 woods, rivers, etc., to be crossed, it is easy to understand that the 

 construction of an aqueduct through that country required many fine 

 works of engineering. The section which traverses the forest of Fon- 

 tainebleau alone comprises three miles of arches, some of them as 

 much as fifty feet in height, and eleven miles of tunnels, nearly all 

 constructed of the material excavated on the spot. So successful has 

 M. Coignet been in his undertaking that other sections of the work, 

 formerly intended to be built of masonry, of cast iron, and of boiler 

 iron plates, have been allotted to him, to be made entirely of his 

 ~bk,ton agglom'ere. 



Hydraulic cement, instead of copper sheets, has been applied to 

 cover the bottoms of ships. Railroad sleepers are being replaced by 

 sleepers of cement. For ornamental work (statues, fountains, etc.), 

 compositions of hydraulic cement have certainly a great future, since 

 the most elaborate forms of art, of great durability and strength, 

 may be most artistically and economically produced in them. For 

 this purpose, only the very best qualities of cement can be used. By 

 the admixture of proper colors, variously colored stones may be 

 obtained. Although this industry, like everything new, had at first 

 to struggle against suspicion and prejudices, it has gradually made its 

 way -by the excellence, beauty and durability of its products, and is 

 now carried on in many places. In the Paris Exposition of 1867, 

 there were statues of Socrates after Tabacchi, the bust of Raphael 

 after Hagni, and Gothic church windows of immense size. Most in 

 demand are, however, door and window caps, ashlars, stoops, window 

 sills, door sills, chimney tops, bowls and tables for wash stands, etc. 

 Artificial rocks, grottoes, inclosures for wells or springs, and cataracts 

 for parks, gardens and hot-houses are also now being produced in 

 cement. Parks which present not a single rock can thus be converted, 

 within a few weeks only, into the most romantic and picturesque 

 scenery. 



Although i%may seem that the application of hydraulic cements was 

 exhaused, many new uses for it will doubtless be discovered. Scarcely 

 any technical journal of importance reaches this side of the Atlantic 

 without containing new information on this topic, and its literature 

 amounts already to scores of volumes. 



I have aimed to dispel some of the prejudices entertained with 

 regard to the use of hydraulic mortars or cements, and to excite 

 a more general interest for the subject. The signs of the times point 



