K. MECHANICS AND ENGINEERING. 397 



i 



tance. The steam of the locomotive can be shut off and the 

 brake of the tender applied, and this acts immediately upon 

 all the other brakes of the train. In cases where the loco- 

 motive was detached from the train and moved off from it, 

 the same result was accomplished. 6 (7, xxxvi.,282. 



EXTER LOCOMOTIVE OR WAGON REGULATOR. 



We have already referred to a steam brake invented by 

 Exter, the general superintendent of railroads in Munich, and 

 we now present a notice of a very simple arrangement lately 

 devised by him for determining the velocity of locomotives, 

 by which the engineer is in a condition to ascertain the rate 

 at which he is moving at any moment, and to appreciate any 

 variation, and thus be enabled to maintain any given rate of 

 speed without the slightest difficulty. 



Without figures for illustration it will be difficult to give 

 a satisfactory account of the apparatus in question, which is 

 contained in a small tin box immediately in front of the en- 

 gineer, and is set in motion by means of a cord extending to 

 the locomotive axis. This indicates, by means of a pointer 

 upon a dial-plate, the rate of movement in miles per hour, 

 and draws at the same time, by means of a lead-pencil upon 

 a moving paper roll visible to the engineer, and receiving its 

 rotation from the motion, a line corresponding to the velocity 

 of movement at any point of the journey. The authorized 

 rate of velocity for any given train is indicated upon this 

 paper disk by means of a line, and any deviation from such 

 rate is appreciable to the engineer, as well as to any other 

 official. The sheets of paper are to be removed at the end of 

 each trip, and held subject to the inspection of the superin- 

 tendent of transportation. The apparatus thus furnishes a 

 graphic representation of the exact rate of the speed of every 

 train at any point in its path ; and these indications being 

 beyond the control of the engineer, an unerring check is held 

 upon his movements, by which he can be brought to account 

 for any improper dereliction of duty. 



By a special adjustment of the apparatus, a second j>encil 

 shows how long the locomotive has remained at any given 

 station, being set in motion while the engine is at a stand- 

 still, and ceasing when it is again started. 



A somewhat similar arrangement has been made by the 



