Any common wright and fmith may make the 

 inflrument. It is very ftrong, very fimple, and 

 eafily managed, and moved from place to place j 

 and if put under cover, will laft many years. 



Fig. II. is the plan of a harrow invented by Mr. 

 Sandilands, which he recommends in a particular 

 manner, and to which he has given the name of the 

 Ojain and Screw Harrow, Its properties are, that 

 if your ridges are high, and you wifh to harrow 

 them froni one end to the other, by lengthening 

 the chain (which the fcrew commands) the har- 

 row, when drawn along, forms an angle down- 

 •wards, and mifles none of the curve of the ridge, fo 

 far as it extends, which may be nine feet, the dif- 

 tance from A. to B. The diftance from C. ta D. 

 is five feet fix inches. When the crowns of the 

 ridges have got what is thought fufficient harrowing 

 ^ iengthwife, you Ihorten the chain by the fcrew, 

 which forms an angle upwards ; the harrow is then 

 drawn by the horfes, one on each fide of the fur- 

 row, which completely harrows it, and the fides of 

 the ridge if eighteen feet broad* 



When you want to harrow even ground or high 

 ridges acrofs, with the fcrew you can bring the 

 harrow to be horizontal, fo as to work as a folid 

 harrow without a joint. 



