54 ANNUAL OF SCIENTIFIC DISCOVERY. 



River at Louisville, which is dostinecl to connect the Kentucky aiul 

 Indiana shores. The bridije itself will be, when finished (and the 

 enirineer in charge expects to turn over his contract lor the build- 

 in;^ some time in November), one of the most splendid structures 

 of the kind in this or any other country. The last span covers 

 370 feet, and is a marvel of engineering skill. 



Jjiidpe over Cape Fear River. — The new iron bridge over the 

 Cnpe Fear River, to connect all the railroad lines centring in 

 "Wilmington, North Carolina, was opened on the 2Sth of August. 



ENGINEERING ITE5IS. 



Resistance of Roads to Traction. — The following results of the 

 experiments of Sir John ]MeNeill, in regard to traction on roads 

 of different kinds, are pretty generally accepted as accurate : 



Resistance in pounds per ton on difterent roads : — 



Iron floor, 8 lbs. per ton. 



Stone tramway, 20 lbs, per ton. 



Paved road, 33 lbs. per ton. 



Macadamized road, 44 to 07 lbs. per ton. 



Gravel, l')0 lbs. per ton. 



Soft, sandy and gravelly soil, 210 lbs. per ton. 



— Van NostratuVs Eng. Mag., Oct., 1869. 



House-lifting. — In the work of straightening and widening 

 some of the crooked streets in Boston, Mass., it became necessary 

 to move a huge building known as ''Hotel Pelham," This build- 

 ing is of freestone, 96 feet high, and weighs 10,000 tons. It was 

 moved 14 feet in 3 days, by means of rollers and screws, a 

 jjortion of the sidewalk being also moved with it. So carefully 

 and well was the work done that not a crack was made in the 

 building, and nothing in it was disturbed. The fastest time ac- 

 complished was two inches in four minutes. A great number of 

 screws 21 inches long were employed. 



The French Cable. — Length between Brest and St. Pierre, 

 2,595 nautical miles, a length that makes this the longest cable 

 ever laid. 



Heavy Blast. — A great blast was lately made at Clitheroe, Eng. 

 A tunnel, 28 yards in length, was bored, and 6,000 lbs. of powder 

 walled in it. The mass of stone, 60 feet in length, was thrown up- 

 wards in a vertical direction, and at least 50,000 tons of limestone 

 displaced. 



An immense Gasometer. — The ^Manhattan Gas Company are 

 building, at the foot of Eleventh Street, in this city, a new gas- 

 ometer of unusually large dimensions. The basin is 225 feet in 

 diameter, and 38 feet deep. The circular wall is 7 feet thick, 

 arranged upon which are 16 elegant guiding columns, each 72 

 feet high, of wrought iron, united at the top by ornamental 

 girders. This will bQ one of the largest gasometers in the coun- 

 try. 



Fog-whistle. —We learn that a fog-whistle, to be worked by a 

 10-horse power engine, is being constructed for Thatcher's Island, 



