78 ANNUAL OF SCIENTIFIC DISCOVERY. 



box, to prevent the escape of the contents. A few or the whole of these 

 scoops may be thus .brought into action at any given moment, the proper 

 depth of water being indicated by a long rod, loaded with a suitable weight, 

 to dredge on the bottom behind. It is well adapted to operating on a soft 

 bottom, when there is deep water conveniently near, in wliich the mud 

 may be dumped. 



PRATT'S DITCH DIGGER. 



At the recent State Agricultural Fair of New York, Mr. R. C. Pratt, 

 of Caiiandaigua, exhibited a new machine for digging ditches, which ap- 

 pears to combine all the elements of success. By its aid, one man and two 

 horses have frequently dug 150 rods of ditch, three feet deep, in one day, 

 and from 50 to 150 (according to the nature of the soil) is considered a 

 day's work. The machine consists substantially of a scoop and revolving 

 wheel, the scoop scraping, and the wheel carrying up the dirt, until at a 

 sufficient height it is tumbled out upon the sides, at a little distance from 

 the ditch. Several repetitions of the operation are required before the 

 ditch is sunk to a sufficient depth. 



The specimen exhibited at the late fair was all of -wrought iron, and 

 weighed between 700 and 800 pounds. The diameter of the main wheel 

 was five feet, and the breadth of the diggers or lifters fixed thereon, and 

 that of the scoop or curved channel in which they rise, is about nine 

 inches. Although the lifting apparatus is thus -narrow, it is practicable, 

 and, indeed, desirable, to make the small ploughs or cutters which pare the 

 side cuts somewhat wider, so that a ditch of any width, from nine to fif- 

 teen inches, may be excavated by the same machine. 



The weight of the dirt which is being lifted, the curved channel, and, in 

 fact, of the whole machine, rests on the diggers, which, like the floats of a 

 paddle-wheel, project from the periphery of the main wheel. As the 

 machine is drawn forward by the horses, the diggers are successively forced 

 into the earth, and compel the wheel to rotate, thus carrying up and dis- 

 charging from the top all the earth caught by the scoop, which is in imme- 

 diate contact behind. On the extreme rear of the whole are adjusted two 

 cutters or small ploughs, which pare the sides, and tear the earth to a suita- 

 ble distance below, ready for the next passage of the machine, so that, after 

 the first passage, the diggers are always pressed down into the ground, 

 already loosened to a depth of from two to ten inches, which loosening 

 maybe supposed to regulate the depth to which they .will be likely to 

 sink. The wheel and its accompaniments being of considerable weight, 

 great muscular exertion would be required of the attendant to pre- 

 vent its falling on one side, but for a simple and very effectual provision 

 for its support. The stout iron shaft on which the main wheel freely re- 

 volves is prolonged some two or three feet on each side, and provided with 

 a light carrying wheel, mounted loose, as in a common carriage axle, to 

 run upon the ground. These wheels are to maintain the upright position 



