AGRICULTURAL MECHANICS AND RURAL ECONOMY. 81 



selves in the carriage under consideration ; only, instead of the alternation of two pair of 

 planks merely, the changes are played on no less than six pair, one pair alone being in plane 

 contact with the underlying ground at one time." 



This machine was exhibited at the recent exhibition of the Royal Agricultural Society, 

 Carlisle, England. Mr. S. W. Johnson, of the N. Y. Country Gentleman, who witnessed its 

 operations, speaks of it as follows : 



" It seems to involve a valuable principle, and excites vast interest. I did not see it in 

 operation, but saw a one-horse cart with wheels rigged on the same plan, which was pretty 

 heavily loaded with tiles, and driven about, backed, and turned short, over ridged and recently- 

 plowed land, and its action was very good. I doubt if the load would have been nearly so 

 easily drawn with a common cart. In crossing the dead furrows, the shoes in a manner 

 bridged the hollow, not allowing the wheels to run so low as they must have done otherwise. 

 This cart is of course mainly intended for soft or plowed land, and doubtless it will not be 

 long in becoming useful and used." 



Farm Steam-Engine. 



A CORRESPONDENT of the Scientific American, writing from Chillicothe, Ohio, states that a 

 portable steam-engine for driving a grain-separator and thrasher, has been constructed in that 

 place and in operation since the 5th of last July, thrashing and cleaning from five to six hun- 

 dred bushels per day. It is capable of doing more than this, but H. Wade for whom it was 

 built says that this is excellent work. The boiler is tubular ; the cylinder is of six inches 

 bore and twelve inches stroke. It makes one hundred and seventy-five revolutions per minute, 

 with steam at forty pounds pressure, and does more work than any common thrashing machine 

 driven by eight horses. It is placed on broad tread-wheels, four feet in diameter, is easily 

 drawn from place to place by two horses, with the boiler filled, and is very economical in the 

 use of fuel. This engine is capable of driving various agricultural machines and sawing 

 firewood for the family. 



Improvements in Rotary Spades and Diggers. 



Gibbs's and Mapes's Rotary Spade. This machine, the invention of Mr. L. H. Gibbs, of 

 Washington, and Professor Mapes, consists of two cast-iron circular plates, about two inches 

 apart ; and working between them are eight stout, narrow, wrought-iron teeth, curved some- 

 what like the old-fashioned cultivator teeth. These teeth are hung, and have a trigger to throw 

 them out as the machine revolves. A yoke of oxen are sufficient to draw the machine, and as it 

 progresses each tooth in succession is pressed into the earth by the weight of the machine : 

 and, when the weight falls upon the trigger, the tooth is thrown out with its load of earth, 

 which is thus mixed and pulverized as thoroughly as if forked over. The two wheels cut a 

 furrow about two feet wide and nine inches deep, which can be increased to any desired width 

 and depth. It requires no holding, yet is provided with handles so fixed as to throw the 

 machine out of the ground. 



Gibson's Digging Machine. This implement, an English invention, which has recently, to a 

 considerable extent, come into use, consists of a number of cylinders, of about three and a half 

 inches in diameter and six inches long, revolving on a fixed axle. On each of the cylinders is 

 cast a disc, twelve inches in diameter, which is furnished with ten teeth or prongs of mal- 

 leable iron or steel, of a curved or cat-claw form, springing from its periphery, and which, 

 partly by the weight of the implement and partly by the strain of draught, is forced into the 

 ground, and, as the implement advances, digs or forces up the soil ; in fact, each prong per- 

 forms precisely the office of a pick or hack in loosening the soil. This forking-up or loosen- 

 ing of the soil is not the only important office of the implement ; but from the curved form of 

 the teeth, it brings all roots and fibrous matter within the depth of its operation to the sur- 

 face ; thus producing a clean as well as a free tillage, or at once acting most effectively as a 

 grubber in bringing up root-weeds, and at the same time performing the most important 

 function of the plow in aerating the soil. The implement is mounted on a strong frame, 



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