Book IV^ 



HARROWS. 



413 



Farmtrs' Society. (See Farm. Mag. vol. xxi. p. 1.) The machine consists of a barrel, 

 which is mounted upon a cart frame, and discharges water from a ball stop-cock having 



four mouths (a) communicating by means of a leathern hose with four horizontal tubes 

 {h h h b), shut up at the end by a screw (c), which admits of the tube being cleaned. 

 The tubes are placed parallel with the drills, two between the wheels of the cart, and one 

 on the outside of each wheel ; the distance of the tubes, and their height from the surface, 

 are regulated by hooks and chains ; and the water is discharged in small streams, through 

 twenty projecting apertures in the under part of the tubes. The tubes are suspended by 

 chains to the hooks in an iron rod secured to the fore and back part of the frame of the 

 cart. The mouth of the funnel on the top of the barrel is covered with a wire-cloth, to 

 prevent any thing getting in to clog the apertures. The quantity of water let out by the 

 apertures being less than what is received into the tubes, the tubes are always full ; by 

 which a regular discharge is kept up from all the apertures at the same time. As the 

 machine advances, the stream which falls from the first aperture upon the plants is 

 followed up by successive streams from all the apertures in the tube ; therefore each plant 

 must receive the discharge from twenty apertures. 



2693. Estimate of its operation. Supposing the barrel to contain 200 gallons, and the tubes to be five 

 feet long, the diameter of the tubes three eighths of an inch, and the diameter of the apertures in the 

 tubes one sixteenth of an inch, 200 gallons will be discharged from 80 such apertures in two hours 

 one third. The diameter of the mouths of the stop-cock must be equal to the diameter of the tubes. The 

 horse, going at the rate of 2^ miles in one hour, in two hours and twenty minutes will go 5 miles five- 

 sixths. The distance between four drills is 6 feet 9 inches; therefore, if we suppose a parallelogram to 

 be 6 feet 9 inches broad, and 5 miles five sixths long, the area of this parallelogram will be 4 acres 3 roods 

 1-6 perches, which will be watered by 200 gallons in two hours and twenty minutes : and in one hour 

 will be watered 2 acres 727 perches, supposing the water to flow uniformly; but the quantity given out 

 upon the drills must be regulated by the progressive movement of the machine. 



2694'. In construction it is neither complicated nor expensive : it may be erected upon the frame of a 

 cart used for other purposes in husbandry ; and the barrel and apparatus may be furnished for about six 

 pounds sterling, supposing the stop-cock and connecting-screws to be made of brass, and the tubes of 

 copper or tin. This machine may be used for other purposes ; such as the application of urine as a 

 manure, or of a solution of muriate of soda, which has been proposed for some crops. 



2695. The best drill machines are French's and Weir's for turnips, Morton's for corn, 

 and the drill attached to a plough (2686.) for beans. 



Sect. III. Harrows or Pronged Implements for scratching the Surface Soil, for 

 covering the Seed, and for other purposes. 



2696. The harrow is an implement of equal antiquity vnth the plough, and has of late 

 years undergone so much improvement as to have originated that class of pronged imple- 

 ments known as cultivators, grubbers, &c. The original uses of the harrow seem to have 

 been chiefly three : that of reducing or comminuting soil already stirred or ploughed ; 

 tearing root weeds out of such soil ; and covering sown seeds. We shall confine our- 

 selves in this section to these three uses. For the purpose of stirring the soil to the 



depth of eight or ten inches and tearing up weeds, no 

 harrow is preferable to that of Finlayson, or Wilkie, in 

 which the tines or prongs are of the cycloidal form. For 

 the purpose of breaking and pulverising the surface of 

 soils, straight prongs, and such as present by breadth or 

 position greater resistance when drawn through the soil, 

 are preferred. It is generally considered that prongs 

 whose horizontal section, a few inches above the point, 

 is a square or a parallelogram (fg. 349.) are best 

 adapted for the attrition to which they are subject in 

 being moved forward in a direction parallel to their 



349 



