ROAD ROLLERS. 229 



pelling, the only track they make is that of the roller, whereas 

 with horse rollers, the hoof-marks of the horses are a great ob- 

 jection. Then again in the amount of work they will do at a 

 certain cost, they excel horse rollers. They may be briefly de- 

 scribed as a sort of locomotive mounted on three or four very 

 broad and heavy wheels, these latter being the road-rollers. 



There are several varieties in use in France and England and 

 two at least of the English kind have been imported into this 

 country, one for the New York Central Park, the other for the 

 Arsenal Grounds in Philadelphia. The cost of the Central Park 

 steam road-roller made by Aveling & Porter of Rochester, Kent, 

 England, was about $5,000, set up in New York, and the amount 

 of work it will do in one day at a running expense of $10, has 

 been given as equal to that of a seven-ton, eight-horse road- 

 roller in two days at $20 per day, or in other words, it will do 

 the same work at one-quarter the running cost and in one-half 

 the time, of a first-class horse road-roller. 



The best horse road-roller of which the writer has any cogni- 

 zance is the one shown by the annexed drawings in plan, eleva- 

 tion and in perspective. (See pp. 230-2-4.) It originates in 

 Chemnitz, Germany, but can of course be easily made by any 

 machine-shop or foundry. The hollow roller is made of cast-iron 

 and is so arranged that it may be filled with water when it is to 

 be used in heavy rolling; when not in use and about to be moved 

 from place to place, the water is allowed to run out, thus mate- 

 rially lessening the load. A circular cast-iron frame A, sur- 

 rounds the roller, and carries the axle bearings of the same. The 

 outside of this frame is turned to form a groove in which a strong 

 wrought iron ring is fitted in such a manner that it will turn 

 easily around the former. This wrought iron ring consists of 

 two semi-circular parts, at whose junction the pole is attached 

 on one side, and on the other an extension bar, carrying the 

 balance weight c, which may be shifted by means of the set 

 clamp rf, or turned up by means of the hinge b. Pins going 

 through the holes at e, fasten this ring or allow it to be turned 

 for the purpose of pulling the roller in the contrary direction, 

 when desired. The brake is shown at/,/, and consists of four 

 wooden brake-blocks, attached by iron shoes to a bar behind 

 them and having rubber packing between the shoes. The screws 

 shown and the handles A, are used to operate these brakes. 



