270 BOAED OF AGRICULTURE. 



twelve feet wide, with driving-wheels ten feet in diameter, 

 and weio;hed seven and a half tons. The inventor claimed 

 that it would haul thirteen ploughs, turning over a breadth of 

 land nineteen feet wide, and plough sixty acres in a day. On 

 trial it broke down after advancing three hundred feet and 

 was condemned. In 1858 Thomas Burridge, of St Louis, 

 Missouri, brought out a machine which on trial, was found to 

 possess sufficient traction-power for the purposes of a hauling- 

 engine, but was so large, heavy and unwieldy in the field as 

 to be of no practical use. In 1863 A. W. Hall, of St. Louis, 

 obtained a patent for, constructed and tried a machine on the 

 principle of rope traction, but it proved to be of no practical 

 use. From 1863 to 1871 invention was busy with the prob- 

 lem of the steam-plough, and several patents were granted, 

 but nothing of practical use was produced. During the past 

 year D. D. Williamson, of New York, has invented a road 

 and field steamer, with Thomson's patent wheels improved by 

 himself, and is now largely engaged in their manufacture. 

 Hitherto the leadino; cause of failure with all traction eno-ines 

 has been to obtain sufficient traction to haul a load, and some- 

 times to even move the machine itself. In this machine the 

 difficulty appears to be surmounted by the peculiar construc- 

 tion of the driving-wheels. These are of cast-iron, five feet 

 in diameter, and sixteen inches breadth of rim or tire. This 

 rim is thickly perforated with half-inch holes, and then sur- 

 rounded with a vulcanized rubber tire four inches in thick- 

 ness ; surrounding the rubber tire is an endless chain of steel 

 plates four inches in width, extending across the rim. The 

 pressure of the machine on the wheels causes the rubber to 

 protrude into the holes in the iron rim and holds it firmly to 

 its place ; the flattening of the rubber on the ground gives it 

 two hundred square inches of traction-surface to each wheel, 

 and its elasticity prevents injury to the engine by concussion 

 in passing over rough roads and fields. The machine has 

 been thoroughly tried the past summer, in various localities, 

 and with unvarying success. Information obtained by cor- 

 respondence with the manufacturer and patentee, with indi- 

 viduals who have witnessed its operations and on whose farms 

 it has been used, indicate that it is capable of accomplishing 

 all that is claimed for it, and that it is the first really success- 

 ful traction engine. 



