30 ANNUAL OF SCIENTIFIC DISCOVERY. 



dergo the real improvement of which it is still capable. Engi- 

 neer. 



THE FAIRLIE ENGINE. 



Mr. Robert Fairlie certainly deserves success, and we have 

 pleasure in believing that he is really commanding it. On two 

 recent occasions in the little "cabbage garden' 1 at Hatcham, 

 another of his great triumphs was exhibited in the trial of the 

 " Tarapaca," a double bogie locomotive of 60 tons' weight, coaled 

 and watered, destined for Peru. The experiments were wit- 

 nessed by some hundreds of eminent official and scientific men, 

 who were all in accord, in so far as we could hear, in their admi- 

 ration of the new engine, which for hours in succession performed 

 the feat, smoothly and with perfect success, of turning round the 

 oval in the gardens, the end curves being of only 50 feet radius. 

 The railway world has heard of Mr. Fail-lie's " Little Wonder" at 

 work upon the Festiniog Railway, and of the triumphs of the 

 "Progress" on the Brecon and Mertly Railway. The " Tara- 

 paca" may properly be designated the " Great Wonder " in the 

 adaptation of steam-power to locomotive purposes. As stated, 

 the engine is 60 tons' weight in working order, or 40 tons' weight 

 when empty ; the bunker-room is sufficient for 30 cwt. of fuel, 

 and the tank accommodation is for 2,200 gallons of water, which 

 should suffice for a 60 miles' run. The weight is equally distrib- 

 uted upon 12 wheels, in 2 groups of 6 each. The wheels in each 

 group are coupled together, so that nil the 12 are driving-wheels, 

 and the whole of the 60 tons is thus made available for adhe- 

 sion. The "Tarapaca" will have to work a gradient of 1 in 26 

 for 11 miles on the Iquiqui line in Peru, belonging to MM. Mon- 

 te ro Freres. The engine has 4 cylinders of 15 inches' diameter 

 and 20 inches' stroke. The wheels are 3 feet 6 inches in diameter, 

 and the brake-arrangement, very powerful, is applied to the 4 

 inner wheels of the 12. The force of the engine at the rails is 

 about 21,400 pounds, or 9 tons, on the level, at a speed of 12 

 miles an hour. The " Little Wonder" runs upon a gauge of 1 

 foot 11A inches; the " Tarapaca" is made for the ordinary 4 feet 

 Sh inches gauge. The Fairlie engine can double the capabilities of 

 any line, irrespective of gauge, its power being double that of 

 engines of the ordinary type. The Festiniog gauge is unduly 

 narrow, and' the ordinary 4 feet 8k inches gauge is wider than is 

 necessary to realize the maximum advantages of the Fairlie sys- 

 tem, which may be secured with a gauge of from 3 feet to 3 feet 

 6 inches. A 3-feet gauge line worked upon this system may be 

 made to carry as many passengers and as many tons of goods as 

 the broadest gauge line in existence, and it can be worked in the 

 ordinary manner, at a speed of from 40 to 45 miles an hour. The 

 dead weight on narrow-gauge lines is much less proportionately 

 than on broad-gauge lines. A wagon for a o-feet gauge, weigh- 

 ing 1 ton, will carry 3 tons of paying weight. The best form of 

 wagon on a 4 feet 8-i-inch gauge weighs from 3 to 5-i tons, and 

 carries from 5 to 10 tons, or about 1.90 ton per ton of wagon. 



