This is especially true as to the arable, which generally forms the most important part of the whole demesne land. There is no exit for a corn trade, and therefore everybody raises corn for his own use, and possibly for a very restricted local market. Even great monastic houses hold only 300 or 400 acres in the home farm; very rarely the number rises to 600, and a thousand acres of arable in one manor is a thing almost unheard of[681]. Husbandry on a large scale appears only now and then in places where sheep-farming prevails, in Wiltshire for instance. Exceptional value is set on the demesne when fisheries are connected with it or salt found on it[682]. [Bockyng, Essex.] The following description of Bockyng in Essex[683], a manor belonging to the Chapter of Christ Church, Canterbury, may serve as an example of the distribution and relative value of demesne soil. The cartulary from which it is drawn was compiled in 1309. The manorial house and close cover five acres. The grass within its precincts which may serve as food for cattle is valued at 8_d._ a year. Corn is also sold there to the value of 12_d._ a year, sometimes more and sometimes less, according to the quantity sown. The orchard provides fruit and vegetables worth 13_s._ 4_d._ a year; the duty levied from the swine gives 6_d._ The pigeon-house is worth 4_d._ Two mills, 7_l._ 1_s._ 8_d._ A fishery, 12_d._ A wood called Brekyng Park, containing 480 acres, and the brushwood there is worth 40_s._ Grass in the wood 12_d._, because it grows only in a few places. Pannage duty from the swine, 10_s._ Another wood called Le Flox contains 10 acres, and the brushwood is worth 6_d._ Pannage from the swine, 6_d._ Grass, 6_d._ Arable, in all fields, 510 acres, the acre being assessed at 6_d._ all round. Each plough may easily till one acre a day, if four horses and two oxen are put to it. Two meadows, one containing eight acres, of which every single acre yields 4_s._ a year; the other meadow contains seven acres of similar value. Pasture in severalty--30 acres, at 12_d._ an acre. Of these, 16 acres are set apart for oxen and horses, and 14 for cows. Some small particles of pasture leased out to the tenants, 4_s._ The prior and the convent are lords of the common pasture in Bockyng, and may send 100 sheep to these commons, and to the fields when not under crop. Value 20_s._