54 ANNUAL OF SCIENTIFIC DISCOVERY. 



fire bricks. This is known as Beattie's system, and he urges that it is com- 

 pletely successful, and that it raises the efficiency of coal to an equality with 

 coke, pound for pound. The fire brick lining in the back side of the fire box 

 would seem necessarily to prevent the generation of an equal amount of 

 steam in the same time, but the performance of the engine as given in the 

 recorded experiments seems to have been very nearly or quite equal to the 

 average of locomotives burning either of the jnore combustible fuels, coke or 

 wood. 



RAILWAY IMPROVEMENTS. 



Loughridge's Self-acting Car Brake. Mr. William Loughridge, of Wever- 

 ton, Maryland, is the inventor of a method of stopping a train of cars at the 

 will of the engineer, radically different from any of the several inventions for 

 the purpose heretofore described. The cars are stopped by the friction 

 of the ordinary brakes, but the power actuating them, is derived directly 

 from a drum shaft on the locomotive. This shaft, or rather a pulley keyed 

 thereon, is pressed into contact with the flange of the driving wheels, and is 

 thus compelled to revolve and wind up a stout chain running the length of 

 the train. This chain applies the brakes of all the cars. TO prevent pulling 

 too severely, and fracturing some portion of the mechanism, provision is made 

 for limiting the extent of its action by causing it to release its hold of the 

 driving wheel so soon as a certain portion of the chain is taken up. The 

 point at which this unshipping movement comes into play is previously 

 arranged by the engineer, so that however excited in view of danger, or care- 

 less and bungling, he cannot endanger the integrity of any important part. A 

 somewhat ingenious arrangement is adopted for causing one continuous chain 

 to supply all the brakes. A stout lever, some three or four feet long, is hung 

 under each car, and provided with sheaves or pulleys at each end, around 

 which the chain makes a curve like the letter S, and continues on to the next. 

 When the chain is pulled by the winding of the shaft, this lever is moved by 

 the tension, and forces the brakes into contact with the wheel. 



Safety Attachment to City Cars. Mr. C. Mahan, of Washington, D. C., has 

 recently patented a device for removing obstructions from before the wheels, 

 and thus to prevent the possibility of crushing any unfortunate child or adult 

 who may fall in a dangerous position beneath the car. It consists of a plough- 

 like attachment on each brake which, by the aid of a point travelling in the 

 groove of the rail and provided with two small wheels, one placed horizon- 

 tally and one vertically to diminish the friction, throws out with a kind of 

 plough-like action every obstacle of whatever nature. In a trial recently made 

 in New York City, the effigy of a man was made up of heavy material so as 

 to weigh 150 pounds, and repeatedly thrown in various positions upon the 

 track, but was in every instance quietly removed without injury to itself or 

 the apparatus. Stones of various sizes were also placed in the grooves and 

 were removed with the same ease. 



Railroad Car Springs. India rubber came quite rapidly into use for car 

 springs a few years ago, but appears now to be going into disfavor. Vege- 

 table gum is not the thing ; it is too lively, and dances a car about too much' 



