ENGINEERING. 



315 



part of the work completed. It has been ob- 

 jected that this method of construction is dan- 

 gerous, but after the arch at Oporto had ad- 







vanced well over the river two successive 

 storms of great violence occurred, causing no 

 damage beyond the demolition of some loose 

 scaffolding. 



Bridge and Viaduct in Russia. A new Russian 

 railway just completed is 285 miles long and 

 connects two of the great lines that terminate 

 respectively at Nicolaiev and Sebastopol on the 

 Black Sea. The new road crosses the Jekat- 



FIG. 2. BRIDGE OF Luiz I. MOUNTING THE ARCH. 



only two European bridges, the Alexandrov- 

 sky over the Volga, and the Moerdyck in 

 Holland. The considerable local population 

 rendered it desirable to pro- 

 vide a carriage- and foot- 

 way, as well as a railway. 

 The 15 spans are each 274 

 feet, giving a total length of 

 4,110 feet to the bridge 

 proper, and the clear height 

 above the water is 43 feet, 

 which is 14 feet higher than 

 the river has ever been 

 known to rise. The car- 

 riage- and foot-ways are 

 30 feet above the railway, 

 occupying the top of the 

 structure. The right abut- 

 ment and the first pier rest 

 upon bed-granite. The rest 

 of the piers, upon caissons 

 sunk to a mean depth of 50 

 feet, and resting partly 

 upon rock and partly upon 

 the white clay of the local- 

 ity. All the masonry of the 

 piers is of granite quarried 

 near by on the banks of the 

 river. At either extremity 

 the bridge is prolonged by 

 viaducts each composed of 

 three spans of parabolic 

 girders which intersect the 

 bridge at an angle to con- 

 nect with the highway, 

 while the railway continues 

 its rectilinear course. These 

 viaducts add 480 feet to the 

 length of the bridge. The 

 total cost was $1,950,000. 

 Into its structure there 

 enter 883,000 cubic feet of 

 masonry and 3,280 tons of 

 Portland cement. The 

 iron- work weighs nearly 10,000 tons, exclusive 

 of the caissons. It has been three years in 

 building. Prof. Belelubsky, of St. Petersburg, 

 superintended the construction with Engineer- 

 in-Ohief Beresin. Under a test of 8 locomo- 

 tives on the rails and a dead-weight of rail- 

 way-iron on the carriage-way, the deflection 

 did not exceed -y^cnr f ^ ne length of each span. 

 Mexican Bridge. Mr. J. Foster Flagg de- 



erine district, and the most interesting engi- scribes, in the " Transactions of the American 



neering features of its construction are a via- Society of Civil Engineers," a bridge built by 



duct over a deep ravine through which runs an ignorant Mexican peon that deserves a place 



the river Juquletz, and a fine bridge over the among the triumphs of modern engineering. 



T\__ __ ~ mi _Ji j_ " _ i T_I _ j? "ijT * T * J . -11 T ilA. ^ ,-. ,-.!-. ^.yl 



Dnieper river. The viaduct is remarkable for 

 its height above the water, as well as for the 



Mexican bridges are usually built of arched 

 masonry, and anything like a truss is unknown 



depth of its foundations. The total length is to the natives. In the State of Colima, 



1,050 feet, and consists of five arches sustaining 

 non-continuous lattice-girders. The track, on a 

 level with the upper plats-bands, is 156 feet 

 above the water and 222 feet above the bottom 

 of the caissons. 

 The Dnieper bridge is exceeded in length by 



bridges of any kind are few, and there were 

 none at all over the river Armeria owing to 

 its depth and rapidity, especially in flood- 

 time. The peon referred to chanced upon 

 a stray number of " Harper's Weekly " con- 

 taining a picture of a suspension- bridge. It 



