For some years the writer had the entire charge of an important railway abroad on which the gradients were very exceptional, and where 48 it was absolutely necessary that he should organize the most complete precautions to prevent the possibility of trains, or portions of trains, running back down inclines. Starting from sea-level, the line, which was laid to the 4 feet 8½ inch gauge, rose to a summit of over 8000 feet, and on the mountain division there were many long gradients of 1 in 40, 1 in 33, and in one place a continuous gradient of 1 in 25 for 12 miles. The specially powerful engines reserved for these heavy inclines were each supplied with an ordinary hand-brake, a steam-brake, and a Westinghouse continuous brake. The passenger carriages, which were of considerable length, and carried on a four-wheeled bogie-truck at each end, were all fitted up with the Westinghouse brake, and in addition each carriage had its own hand-wheel brake with the pawl and ratchet gearing. All the goods waggons, which were of the American type, were fitted with hand-wheel brakes similar to those on the carriages. Special gangs of trained brakesmen took charge of the trains on these inclines, a brakesman to every carriage or waggon, and were always in readiness in case of the breakage of a coupling, or the failure in the Westinghouse brake or brakes on engine. The immunity from accidents justified the combined precautions adopted, and proved the possibility of working such severe gradients with perfect safety. The long-continued application of the brakes on heavy inclines naturally leads to the question as to the description of wheel to be adopted for the work. Not only are the wheels subjected to very severe torsional strains, but the temperature at the circumference is raised very high in consequence of the friction. Perhaps, theoretically, the safest wheel would be one made out of a solid piece of metal, similar to the chilled cast-iron wheels of the United States, or the steel disc wheels used on some lines in Europe, in either of which holes can be left for sprags. Wheels of this description can withstand very heavy wear and tear, they are not affected by increased temperature, and they certainly have the minimum of parts to work loose. Of the built-up wheels, the strong forged-iron-spoke wheel with steel tyres shows excellent results, and always gives due warning of loosening by indications at the tyre rivets. The suddenness with which the solid wooden centre wheels sometimes break up and fall to pieces does not commend them for a service where there must be a long-sustained application of the brakes. The increased temperature which expands the 49 tyre, contracts the wood, and must loosen and weaken the entire wheel.