496 



MECHANICAL IMPROVEMENTS. 



strains on the curves. It can be run back- 

 ward or forward, and is provided with brakes 

 which stop it almost instantly. By an im- 

 provement a bogie truck at the opposite end 

 from the driving-wheels reduces the rigid 

 wheel-base to three feet, and has an apparatus 

 connected by which the car can be guided 

 upon the sidings without employing movable 

 switches, and can also be turned off the rails 

 when necessary and brought back upon them 

 again. The exhaust steam is conducted into a 

 copper chamber fixed in the uptake of the boil- 

 er, and expands and escapes superheated. The 

 arrangement for condensing the steam makes 

 the car noiseless. A comparison of expenses 

 has been made which shows that steam tram- 

 cars of either the Grantham or Merryweather 

 pattern afford a saving of 33 to 50 per cent, 

 over horse-traction. A novel device, which has 

 been worked up by General John A. Imboden, 

 consists in a steam motor which can be attached 

 to an ordinary horse-car. It has four driving- 

 wheels, with a wheel-base of four feet. It can 

 be attached to a car by a pivot, after removing 

 a pair of the car-wheels. 



The tooth-wheel system of locomotive en- 

 gine, in which cogs in a central wheel under 

 the locomotive fit into indentations in a third 

 track, has proved the best so far for grades 

 too steep for the adhesion of the wheels on a 

 smooth track. This system, which has been 

 many years in use on the excursion roads up 

 the Eighi in Switzerland and up the side of Mt. 

 Washington, has never until the present been 

 utilized for goods transportation since the very 

 infancy of steam locomotion, when, in 1811, the 

 Englishman Blankinsop constructed a tooth- 

 wheel locomotive which propelled a coal-train 

 up an incline of 7 in 100. After the triumph 

 of Stephen son's system this method of propul- 

 sion was forgotten, until, in 1852, Baldwin 

 constructed a similar engine in America, and 

 in the same year Marsh proclaimed his proj- 

 ect for a tooth- wheel track up Mt. Washington, 

 with an inclination of 1 in 3 ; this scheme was 

 treated as the greatest folly, and it was not un- 

 til 1868 that it was carried out. In the mean 

 time Riggenbach had been advocating a rail- 

 road up the Righi, and when it was known that 

 the American road had been built, his scheme 

 was first listened to. In 1871 the Righi in- 

 clined railroad was built, according to the mod- 

 els patented by Riggenbach in 1862. Between 

 two ordinary rails is a third one, similar to a 

 ladder, with teeth, in which the cogs of the 

 toothed wheel catch. The power required to 

 pull the train, with this arrangement, is con- 

 siderably less than where the propulsion is by 

 friction, and the weight of the engine can be 

 greatly reduced. An incline of 1 in 4 can be 

 ascended with a tooth-wheeled locomotive, 

 and on lesser grades a much greater load can 

 be drawn. This system has lately been em- 

 ployed on the Hollenthal Railroad in Germa- 

 ny. The engines are calculated to draw 3 

 times their weight up a grade of 5 in 100. The 



locomotives are constructed to run on ordinary 

 roads by means of common driving-wheels, the 

 toothed wheel remaining then idle. The ve- 

 locity, when the toothed wheel is in use, is 

 much less than on the level road, but the as- 

 cent is made in as short a time as, or shorter 

 than, if the road had been built with an ordi- 

 nary grade in a serpentine course, while the 

 amount of fuel consumed, the wear and tear of 

 the machinery and road, and the cost of con- 

 struction, are very much lessened. 



The great importance of the continuous sys- 

 tem of railway brakes to the security of the 

 traveling public is being recognized in Europe, 

 where continuous brakes have not yet been 

 generally introduced. Th e Governments of Ger- 

 many, Great Britain, and Belgium instituted 

 experiments on the different forms of brake 

 offered in the market, which have been per- 

 formed within the year, and the general results 

 of which are given below. The Smith and 

 Westinghouse brakes, which are rivals for the 

 supremacy, are both of them Amercan inven- 

 tions ; the former has been some time in use 

 in England. The report of a Belgian commis- 

 sion appointed to examine into the merits of 

 safety railroad brakes designates the Westing- 

 house automatic and Smith's vacuum brakes as 

 the most perfect. The Westinghouse in five ex- 

 perimental trips brought the train to a stand- 

 still in an average distance of 781 feet, while 

 running at an average speed of 39 miles an 

 hour ; while the vacuum brake, applied at an 

 average rate of speed of 38.5 miles, arrested the 

 train at an average distance of 1,153 feet : they 

 thence calculated the retarding force of the au- 

 tomatic brake as 728 kilogrammetres, and of 

 the vacuum as 437 kilogrammetres. The cost 

 of the vacuum brake is more than 40 per cent, 

 less than the automatic, but the commissioners 

 consider that the difference is more than coun- 

 terbalanced by the greater expense of keeping 

 in repair and working the former, which re- 

 quires a greater amount of steam and fuel. A 

 British commission appointed for the same pur- 

 pose by the Board of Trade in 1874, reported 

 recently that it was necessary to introduce 

 continuous brakes on British roads, without 

 recommending any special kind. Sir Henry 

 Tyler, who was the first to introduce this ques- 

 tion, 12 years ago, has estimated that during 

 the 12 years past as many as 600 deaths have 

 resulted from railway accidents of a kind which 

 might have been prevented by the use of con- 

 tinuous brakes. A case in which two trains 

 were saved from serious accidents by the use 

 of the Westinghouse brake occurred on the 

 Midland Railway in August. In a trial of 

 continuous brakes at Cassel, made at the 

 command of the German Government, special 

 attention was paid to the rapidity with which 

 the brake affects the speed of a train. The 

 experiments were made with the Westing- 

 house automatic, Smith's vacuum, Steel's, and 

 Heberlein's brakes, upon a down grade and 

 on a level, at 75 and 90 kilometres (46.6 and 



