36 ANNUAL OF SCIENTIFIC DISCOVERY. 



Length of main span from centre to centre of towers, 1,057 feet. 

 Leni^th of each land span, 281 feet. 



Total k-n-^'th of bridge, including approaches from Front Street in Cincinnati 

 and Second Street in Covington, 'l,'1.^2 feet. 



Height of towers from foundation, without turrets, 200 feet. 



Height of turrets, 30 feet. 



Height of bridge above low water, 100 feet. 



AViilth of bridge in the clear, 30 feet. 



Number of cables, 2. 



Diameter of cables, 12.-} inches. 



Amount of wire in tho cables, 1,000,000 pounds. 



Strength of the structure, 10,800 tons. 



Deflection of cables, 88 feet. 



Masonry in each tower, 32,000 perches. 



Jhisunry in each anchorage, 13, 000 perches. 



Masonry, total amount, 1)0,000 perches. 



Towers at base, 80 by .'>2 feet. 



Towers at top, 74 by 40 foot. 



Strands in each cable, 7. 



AVires in each strand, 740. 



Wires in cables, total, 10,3G0. 



IVeight of wire, "lOO tons. 



Foot of lumber, «iOO,000. 



GREAT VIADUCTS. 



At a mcotin.!^ of the Society of Engineers, in January, 18GG, a 

 pajit'i- -was read by i\Ir. W. II. INIill.s, on the Cralgnllacliie Viadiiet. 



Thi.s via(hict "vvas construct(.'d lor the puri)ose of carrying llie 

 Moraysliire Railway over the River Spey, at Craigelhiehie, Banft- 

 pliirt',' tiie engineers being Mr. Samuel (M. Inst. C. E.) and the 

 auliior. It consisted of tiu'ee spans of o7 feet each on the north 

 bank, and one si)an of l'DO feet over the main channel of the river; 

 ordinary boiler-plate girders constituting the former, and the lat- 

 ter being of wrought-iron on the lattice principle. The piers and 

 abutnu'uts Avere of solid ashlar masonry, and the works were ar- 

 ranged for a single line of railway. It appeared that tlie excava- 

 tion for the foundations was commenced in May, 1862, and that 

 the viaduct was opened for public tralli(! in July, 1863. The total 

 cost had amounted to £1l',1[)'J, or equal to £29 10s. per lincsal foot. 



A paper was also read at the same meeting !)y Mr. Ridley, giv- 

 ing some details concerning the Grand River Viaduct, Mauritius 

 Railway. 



It was stated that the length of this viaduct, from almtment to 

 abutment, Avas 620 feet, and that this distan<;e was diviihnl into 

 five openings of 116 feet each in the clear. The height from the 

 level of the rails to the surfixce of the water w^as 129 feet 9 inches. 

 Each \)WY was composed of two cast-iron cylindei-s, each ten feet 

 in diameter, resting upon masonry foundations, and filled with 

 concrete ; the works being for a single line of railway. 



GREAT BRIDGES. 



The Victoria Bridge over the St. Lawrence, at Montreal, has a 

 total length of one and three-quarters miles, and a length of iron 

 tubing of one and one-quarter miles, with 25 spans, one of 330 



