238 



Each one of the elementary parts is nothing more than a rack 

 in its simplest form, or a bar of iron or steel provided with 

 teeth. Whatever may be the tractive power to be developed 

 by the pinion working in the rack, by placing side by side the 

 proper number of bars, each one is strained only to its chosen 

 limit. The bars are connected by chairs and bolts, by which 

 they are secured to the road bed. The bars are laid with broken 

 joints, so that the teeth of one bar are slightly in advance of 

 those in another. The pinion is similarly constructed of discs, 

 and are stepped to suit the teeth in the rack. The discs have 

 elastic springs of rubber between them and the shaft to which 

 they are fixed, thus admitting of adjustment to any imperfec- 

 tion in the accurate manufacture of the racks. This works so 

 well that at a speed of sixteen miles an hour there is no noise or 

 blow whatever. 



One characteristic feature in the system is the adaptation of 

 the rack to the steepness of the gradient, the number or thick- 

 ness of the elementary bars being chosen according to the 

 traction required. Curves can also be easily traversed, which 

 is not the case with the ordinary rack rail. This system has 

 heen most successfully used on the Hertz Eailway, Prussia, and 

 is being applied to the Hollenthal Eailway, South G-ermany, 

 and on the extensive slate quarries connected with the Bavarian 

 State railways. 



SHIP BAIL WATS. 



An American engineer of some celebrity (Captain Eads) has 

 conceived the idea of transporting ships overland by means of 

 railways, and although considerable opposition has been offered 

 to the scheme by engineers, it has been approved by Congress. 



It seems to me a very difficult problem to solve, bearing in 

 mind the enormous weight of the vessels now built, including 

 their machinery and cargo, and it is difficult to conceive how 

 the very large number of wheels required to carry this load 

 without straining the ship can be moved over rails unless they 

 .are laid on an unyielding foundation with mathematical accu- 

 racy. The locomotive power to move such a mass would also 

 be very great. 



There is, however, a ship railway now under way from the 

 Gulf of St. Lawrence to the bay of Fundy, and another is pro- 

 jected across the Florida Peninsula. 



PANAMA CANAL. 



Among the great works in progress may be mentioned the 

 canal across the Isthmus of Panama. Grrave doubts are ex- 

 pressed by many eminent American eugiueers as to the possi- 

 bility, or rather the probability, of the successful completion 

 of this great undertaking. Great faith is placed by the 



