Cultivation of Grafs Land. Drinking Pond* Forma proper for. 



-conveyed into them, from forne road, or other firm furface; many are, however, 

 placed without any fuch afildance for filling, or with very little, it being found 

 that the rain that falls upon their furfaces is in general furncient for a fupply, 

 after they have been once filled :* but in many cafes, as the expenfc is con- 

 iiderablc, it would feem more advantageous to have them formed in the angles of 

 corners, where two or three fields meet, as by this means one pond may fcrve the 

 whole, and at the fame time but little fpace of ground be taken up or waded. It 

 has been fuggefted as highly ufeful in the forming of thefe drinking-ponds, to have 

 a wade-water place on the upper iideof the main rdTervoirs, to prevent their being 

 ufelefsly fitted up when full by the muddy water continuing to run into them ; 

 as by its changing from a running to a dagnant date a confiderablc depofit takes 

 place, which might thus be avoided. f Much mud would alfo be collected in 

 this way, in many cafes, and be removed with little trouble ; which renders them of 

 great utility in procuring manure. 



It has been obferved that &quot; the bed feafon for making thefe ponds is thought to 

 be in autumn, as they are then likely to be filled the fooned, and the lead liable to 

 crack before they are filled. Should the weather prove dry at the time they are 

 finifhed, it is well to cover their furfaces with draw, or litter, to hinder them from 

 ** cracking.&quot; And &quot; as it is deferable to get them filled as foon as pofilble after they 

 are finifhed, fnow is frequently collected and heaped upon them, if pofiible, in large 

 quantities, the fird winter after they are finifhed, for that purpofe.J&quot; 



The form of ponds for this ufe is in general that of a mallow bafon, the fides 

 {helving in a gradual manner from the brim to the centre. But other forms 

 may be adopted according to circumdances. In the fird mode, where the excava 

 tion is fixty feet in diameter, the greated depth is about feven ; but when only- 

 forty feet in diameter, the depth is modly about five, before any of the coats arc 

 applied.^ There would feem, however, to be an advantage in having fuch ponds 

 of greater depths and lefs diameters, as it is well afcertained that the quickncfs 

 of evaporation is in a great meafure in proportion to the extent of furface that 

 is expofed to the influence of the atmofphere: of courfe fuch ponds as have great 

 diameters with little depths, mud become dry in hot feafons much more quickly 

 than where the contrary is the cafe. 



In fetting out ponds of this fort, the ufe of the level will be necefCuy ; dakes 



* Corrected Report of the North Riding of Yorkshire. f Ibid. J Ibid. Ibid. 

 VOL.11, 3 Q 



