372 TRANSACTIONS OF THE 



2. Harrows worked in a similar manner. 



3. Land cultivated by means of chains, having tines or grubbers 

 fixed in them, w^orking longitudinally over two vertical pullies, 

 one at each end of the machine. 



4. An endless chain passing over horizontal pullies or carriages 

 placed, along the field, one pulley being on each carriage. 



To one side of the endless chain, a plow is attached, and works 

 alternately between two carriages, the carriages being moved for- 

 ward as the work proceeds. Thus a carriage on four wheels, one 

 at each end or side of the field, and a locomotive or portable en- 

 gine in the centre with endless chf^in and two plows, would form 

 the details for plowing a piece of land. 



In 1812, Messrs. Chapman patented a steam-carriage with a 

 "rigger'' working on a stretched chain or rope secured at both 

 ends by anchors. This principle of "rigger-traction'' for giving 

 motion to plows has been carried out under numerous modifica- 

 tions by many inventors, and very recently with considerable 

 success. 



In 1832, Joseph Saxton patented a system of differential pul- 

 lies, partly applicable to the working of plows — an endless rope 

 being used to give motion to a windlass, to which the plows, &c. 

 were attached. 



In the same year, John Heathcot of Tiverton, in Devon, pat- 

 ented a plan of plow-traction by means of a direct pull from a 

 stationary engine. One end of a drag rope is fixed on to a long 

 drum, situated horizontally over the boiler, and in length, equal to 

 the length of the field, coiled upon it. The rope then passes to 

 the opposite head- land round a large pulley there of an auxiliary 

 carriage which serves for an anchor. The rope then returns and 

 is fixed to the opposite side of the long drum. To one side of 

 this rope the plow carriage is fixed, the drum is then set in mo- 

 tion when it coils up one end of the rope as it gives off the other, 

 the engine -carriage and auxiliary carriage moving opposite head- 

 lands as the work of plowing advances. 



In 1850, Mr. Jiames Usher, of Edinburgh, patented a series 

 of plows in the same plane round an axis, so that the plows suc- 

 cessively come into action; secondly., giving rotatory motion to a 

 series of plows, or rather instruments, (Mapes' digger,) to till 

 the earth. 



We have by no means exhausted the plans and patents for this 

 object. The most important is " Boydell's Endless Railway.'' 



Drawings are given of Usher's rotary digger, (Mapes.) 



