-174 
Report on the Exhihitioa of Implements 
which is again highly commended for its strength, lightness, and 
adaptation to general purposes. 
A harrow constructed on an original principle was produced 
by Mr. Robert Hopkin, of Hartington, near Ashbourne, Derby- 
shire, which appeared on trial to be worthy of encouragement, 
and 5/. were awarded to the ingenious inventor. The harrow is 
circular, like a cart-wheel, and lies flat on the ground, the tines 
passing through the felloes. A horizontal revolving motion is 
communicated to it, as it is drawn forwards, by means of an 
endless chain proceeding from a carriage in advance, and passing 
round a pulley fixed upon, and concentric with, the rim of the 
harrow, but of smaller diameter. The power is derived from the 
carriage-wheels, as in other cases. The execution of the appara- 
tus was very imperfectly adapted to give effect to this novel idea, 
but the principle, perhaps, merits the attention of mechanics, as 
the double action compounded of the progressive and circular 
movements appeared to produce a very considerable comminution 
of the soil. Several circles of teeth may be inserted in the same 
wheel, and if it be found that the power used in giving the spin- 
ning or revolving motion be paid for in the quantity or quality of 
the effect, this construction might prove advantageous as a sur- 
face-pulverizer. The experiment should be made with short 
small teeth. 
Mr. Smith's (of Deanston) chain-brush or web-harrows, re- 
warded at Liverpool, were exhibited by Messrs. Cottam and 
Hallen, of London, with a change in the structure of the cd^e of 
the rolling-rings, or discs, the latter being notched or serrated 
instead of plain, and therefore presenting increased abrading 
surface. The harrow tried was 5 feet square, covering, therefore, 
an area of 25 square feet, and weighing 392 lbs. This imple- 
ment is adapted for merely superficial operations, such as covering 
small grass-seeds, &c., as it rubs or brushes the finest pulverulent 
soil upon the seed ; in addition to which it acts as a light com- 
pressor or roller, for, though the direct pressure is only about 
16 lbs. per square foot, this weight continues to act through 5 feet 
in the space passed over, and tends to set down the earth upon 
the seed, which the common harrow cannot effect. It may also 
prove useful for spreading and pulverizing manure laid upon 
meadow-land in the winter, and for operations where the teeth of 
harrows might be injurious or unsuitable. It is right that the 
Judges should observe that they noticed its action at a time 
when the clay soil at Rough Heanor was very dry, and in a pe- 
culiarly fit state for displaying its good qualities. A silver medal 
was awarded to ]Mr. Cotlain for his improvement. 
A variety of other harrows was offered to the agricultural 
Avorld, among them a new lever-harrow, by Mr. Joseph C. Grant, 
