Page:The American Cyclopædia (1879) Volume III.djvu/212

 206 BRAKE BRAMANTE D'URBINO FJQ. 1. formerly an instrument of little importance, and prior to 1835 only one patent for a brake was granted in the United States. Since the adoption of high speed upon railroads the sub- ject of brakes has become one of great interest. There are two kinds used on railroad carriages, the ordinary brake for stopping the train at stations, and the safety brake, which may be applied instantaneously to the wheels of all the carriages on a train for the purpose of bringing it to a sudden halt. The ordinary car brake consists of a friction block, a lever, a chain and rod for moving the lever, and a windlass upon the platform of the car. The general plan and principle of action are represented in fig. 1, where a is the wheel turned by the brakeman, s the shaft around which the chain c is wound, forming the windlass, which by the action of simple levers draws the friction blocks & J, fig. 2, against the peri- phery of the wheel. The application may be made in various ways. Of the safety brakes there are several, but they may all be divided into three kinds : the first, in which the power is derived from a coiled spring ; a second, in which it is derived from compressed air contained in a cyl- inder ; and a third, in which electro- magnetism is the motive power. All these brakes employ the same friction block and leverage, which is connected with the windlass ordinarily turned by the brakeman. What is known as the Crea- mer brake, which is extensively used in the Uni- ted States, employs a spiral spring as the motive power. This spring is coiled in a drum, which is placed upon the platform of the car, and through the drum passes the shaft, which is turned by the brakeman. The general arrange- ment is represented in fig. 3, in which d is the drum containing the spring, the shaft, and c the chain (corresponding to and c in fig. 1). The spring is wound up by means of a special attachment to the shaft turned by the brake- man, which can be con- nected or disconnected at pleasure. A cord, r, is attached by one end to the rope which passes through the train, and by the other to the lever FIG. 2. FIG. 3. I, which on being pulled by the cord libe- rates the spring, causing it to exert its force through the chain and lever upon the fric- tion block, drawing it against the wheel. The compressed air brake used in the United States FIG. 4. is known as the Westinghonse air brake, and is made at Pittsburgh, Penn. Under each carriage there is placed a cylinder, fig. 4, 18 or 20 inches in length and about 8 inches in di- ameter, which is connected by metallic pipes and india-rubber tubing with a reservoir of compressed air attach- I cil to the engine, and which by a 'force pump receives a pressure of about 60 Ibs. to the square inch. When the engineer wishes to bring the train to a sudden stop, he opens a valve leading from the air chamber to the various cylinders under the carriages. The air rushes through the tubes, and, pressing upon the piston heads, moves them. By a connec- tion with the piston rods the friction blocks are forced against the wheels simultaneously throughout the whole train. An electric brake, devised by M. Achard of Paris, is described in President Barnard's " Report of the Paris Ex- position of 1867," but it does not possess the practical advantages of either the Creamer or the Westinghouse brake. I'.UAkKMSI U<;, Regner, a Dutch painter, born at Haarlem about 1650, died there in 1702. He selected his subjects frequently from low life, which he illustrated with great truthfulness and humor. His pictures are .numerous in France and the Low Countries. BRAMAH, Joseph, an English engineer, born at Stainborough, Yorkshire, April 13, 1749, died Dec. 9, 1814. He showed at an early age a remarkable mechanical ingenuity, was ap- prenticed to a carpenter, and subsequently re- moved to London, where he worked for a cabinetmaker, and afterward set up in the same business for himself. In 1784 he took out a patent for his widely renowned locks. Among many other inventions, he devised the hydraulic press, which is used not only in the ordinary mode of a press, but also for lifting enormous weights. He was the inventor of a mode of printing the number and date of bank notes used in the bank of England, by which the ser- vices of 100 clerks out of 120 were dispensed with. In 1812 he secured a patent for the construction of main pipes through the princi- pal streets of a city, of sufficient strength to withstand great pressure to be applied by force pumps. The object of this invention was to provide the means of extinguishing fires with- out the aid of a fire engine. I!K Mvn: D'URBIJfO, an Italian architect, whose real name was DONATO LAZZAKI, born at Monte Asdrualdo, near Fnmignano, in 1444, died in Rome in 1514. At an early age he was placed as pupil with Fra Bartolommeo, and several of his pictures are still preserved at Milan. Having gone to Rome, he executed a few frescoes, but his taste was wholly for ar- chitecture, and his study of the antiquities of the city confirmed this bias. His erection of