29 tons 8 cwt. The valve gear is of the Walschert type. The engine has an extended smoke box. The following details may be quoted:

The haulage power of this locomotive was calculated on a basis of a train-load, exclusive of engine, of 151 tons taken up a gradient of 1 in 57, at 1036 tons* on the level and straight, and at 276 tons on the proposed ruling gradient of 1 in 100 on a curve of 600 ft. radius. As a matter of actual performance at Newlay the engine hauled 190 tons up the gradient of 1 in 57, so that the theoretical figures have been favourably under-estimated.

For purposes of comparison it may be mentioned that the Cooch Behar State Railway locomotives, on the same gauge, have a grate area of 5 18 sq. ft., and cylinders 8 in. diam. by 12 in. stroke; carry 400 gallons of water and 20 c. ft. of fuel (about half a ton of coal, for example); have six wheels coupled on a base of 8 ft. 6 in.; and were required to haul only 275 tons on the level. The axle-loads on the coupled wheels amount to 13 tons 4 cwts. 3 qrs. on a wheel-base of 8 ft. 6 in., as compared with 19 tons 15 cwts. on a wheel-base of only 8 ft. 3 in. on the Barsi Light Railway. The Cooch Behar State Railway was designed for less work and lighter rails and bridges, the weight of the rails being only 25 lbs. per yard.

To combine the maximum haulage power with a uniform axle-load of 5 tons has been the leading motive in the design of the Barsi engines. It is scarcely correct to say that this has saved the weight of the rail, for that does not depend only on the maximum axle-load on any one pair of wheels; and it has been accomplished by the concentration of a greater weight within a shorter base, which has made it necessary to strengthen or replace the bridges.

In designing the wagons the object has been to combine the maximum carrying capacity with the minimum tare weight. Of the wagons (Plate VII. figs. 3, 4, 5) there are three patterns-the covered goods wagon, the high-sided coal wagon, and the low-sided or platform goods wagon. In accordance with Mr Calthrop's principle-which our locomotive superintendents in India now generally recogniseidentity and interchangeability of parts and uniformity in dimen

Engineering, October 30, 1896.

The following

sions, wherever possible, are regarded as essential. details are common to the three kinds of goods stock :—

All three sorts of wagons are of the bogie type, and built throughout of Fox's pressed steel. The makers claim that, although wagon and bogie frames of pressed steel might cost £6 5s. per ton, as against £5 15s. for channel steel, they are lighter by about 15 per cent. on bogies and 10 per cent. on frames, they consist of fewer separate pieces, and they require fewer knees and less riveting; they suffer, therefore, less from vibration and corrosion, and accordingly last longer. On the other hand, it appears to the writer that repairs and renewals of parts can be more easily effected on built-up frames. Of the two types of bogies the non-bolster type would seem to be quite good enough for 2 ft. 6 in. gauge stock; its weight is made up as follows:-Cwt. Qrs. Lbs.

The swing-bolster type weighs, with brakework as above, 25 cwts. 2 qrs. 10 lbs. The wheels have a diameter, on their tread, of 1 ft. 11 in. The high-sided wagon has a capacity of 1000 c. ft. All are fitted with a hand brake which can be applied or taken off from either side of the vehicle; the brake is applied to one bogie only.

The length of the composite passenger car (Plate VII. fig. 6) is 43 ft. 3 in. over buffers, and 40 ft. over head-stocks. The distance between centres of bogies is 28 ft. The bogies and under-frames are of pressed steel. The body of the car was made by the Lancaster Railway Carriage and Wagon Company; is 40 ft. 6 in. long, and 7 ft. 6 in. wide over the sunshades, with a clear width of 6 ft. 2 in. inside ; and is divided into luggage and brake compartment, an upper-class compartment with sleeping-berths and lavatory, and a lower-class compartment with transverse seats. The end platform and centre gangway pattern has not been adopted, nor did the writer see carriages with open sides and awnings or tarpaulins hung as required, such as are frequently used on narrow-gauge lines in India and on the Continent. Sunshades are absolutely necessary in a country like India. There is a brake on each bogie, one worked directly by the hand wheel in the compartment, the other indirectly, but with equal effect,

through a pull-bar connection. The over-hang is such that, on the 2 ft. 6 in. gauge, we have here coaching stock 6 ft. 8 in. wide over pillars, as compared with a width of 8 ft. 0 in. on the standard 4 ft. 8 in. gauge; the height, too, is ample, being 10 ft. from rail level at the centre, and 9 ft. at the sides. A flexible buffer coupling has been adopted, permitting a radial movement through an angle of 36 degrees, so that the stock can be admitted to sidings on curves with the maximum radius of 150 feet.

The line at the Newlay Exhibition of Barsi Light Railway stock in October 1896 was laid with 30 and 35 lb. Vignoles rails on steel sleepers, supplied by the Moss Bay Hæmatite Steel and Iron Co., Workington. A diagram of the trial train is shown in Plate VII. fig. 1. The wagons and cars took the 150 ft. radius curves without difficulty, while the engine was able to manage curves of 250 ft. radius nominally, but in places much sharper, measurements made by the writer indicating radii of 190 and 210 ft. at two points chosen at random. An actual load of 190 tons* was taken up a gradient of 1 in 57. There is no doubt, therefore, that the engine can work the train-load of 260 tons on the ruling gradient of the Barsi Light Railway as required; a load which would, on a passenger train, provide accommodation for 30 upper-class and 736 lower-class passengers, while, with 12 goods wagons and a brake van, its capacity would be equal to 190 tons of goods and 38 passengers. Mr Calthrop mentions this in support of his contention that the 2 ft. 6 in. gauge "possesses the greatest carrying capacity per cent. of capital cost."

In actual use in India, the usual train-load is one lower-class carriage and one composite brake, with nine loaded goods wagons, making up a gross load of about 210 tons.

The consumption of water is about 30 gallons, and of coal about 4.1 lbs. per mile per vehicle (including the engine).

The cost of the rolling-stock delivered at Bombay (taking the rupee at 15d.) was as follows:

The cost of this 2 ft. 6 in. gauge locomotive, therefore, is greater than that of an ordinary F class metre-gauge engine. Its tractive power is about the same. Its wheels are smaller, and it has a greater ratio of length of stroke to diameter of wheel, and is only suited, therefore, to run at a much lower speed. It brings nearly as much adhesion weight on a shorter wheel-base, 19 tons on 8 ft. 3 in., and, the axles being so close together, a heavier load on each sleeper.