is 27 lb. per mile, or 8 lb. per mile less than the standard coupled engine of the North-Western with similar loads.  Mr. Stirling’s view, that the larger the wheel the better the adhesion, seems borne out of these facts; thus to take twenty-eight coaches, or a gross load of 345 tons, up 1 in 200 at a speed of 35 miles an hour, would require an adhesive force of 8,970 lb., or 600 lb. per ton—­more than a quarter the weight on the driving wheels.  These engines are magnificent samples of the most powerful express engines of the present day.

The London, Brighton, and South Coast Railway Company has in the last few years had its locomotive stock almost entirely replaced, and instead of seventy-two different varieties of engines out of a total of 233, which was the state of locomotive stock in 1871. a small number of well-considered types, suited to the different class of work required, are now in use.  Mr. Stroudley considers—­contrary to the opinion once almost universally held—­that engines with a high center of gravity are the safest to traverse curves at high speed, as the centrifugal force throws the greatest weight on the outer wheels, and prevents their mounting; also that the greatest weight should be on the leading wheels, and that there is no objection to these wheels being of a much larger diameter than that usually adopted; in fact, by coupling the leading and driving wheels where the main weight is placed a lighter load is thrown on the trailing wheels, thus enabling them to traverse curves at a high speed with safety, while it permits of a larger fire-box being used; and these principles have been carried out in the newest class of engines, especially designed for working the heavy fast passenger traffic of the line.

The modern express engines are of two types.  The first is a single engine with 6 ft. 6 in. driving wheels, and leading and trailing wheels 4 ft. 6 in. in diameter and a wheel base of 15 ft. 9 in.  The frames are single, with inside bearings to all the wheels; the cylinders are inside, 17 in. diameter and 24 in. stroke.  The boiler is 10 ft. 2 in. long and 4 ft. 3 in. diameter; the fire-box is of copper with a fire-grate area of 17.8 square feet, and the heating surface is in the tubes 1,080 square feet, fire-box 102 square feet; total, 1182 square feet.  The weight in working order is about 35 tons.  These engines have a tractive power of 89 lb. per pound of mean steam pressure in the cylinders, and their consumption of coal with trains averaging nine coaches is about 20 lb. per mile.  The next type of engine designed has coupled wheels under the barrel of the boiler 6 ft. 6 in. diameter, with cylinders 171/4 in. diameter and 26 in. stroke, and were found so successful that Mr. Stroudley designed a more powerful engine of the same class, especially to take the heaviest fast trains in all weathers.

The 8:45 A.M. train from Brighton has grown to be one of the heaviest fast trains in the kingdom, although the distance it runs is but very short, while it is also exceptional in consisting entirely of first class coaches, and the passengers mainly season ticket holders; it often weighs in the gross 350 tons, and to take this weight at a mean speed of forty-five to fifty miles an hour over gradients of 1 in 264 is no light work.