if one deducts forty jugera, or one-sixth, from Cato’s two hundred and forty jugera, I do not see how in applying this rule one can deduct also one-sixth of his thirteen slaves; or, even if we leave out the overseer and the housekeeper, how one can deduct one-sixth of eleven slaves.  Again, Cato says that one should have fifteen slaves for one hundred jugera of vineyard, but suppose one had a centuria half in vines and half in olives, then, according to Cato’s rule, one would require two overseers and two housekeepers, which is absurd.  Wherefore it is necessary to find another measure than Cato’s for determining the number of slaves, and I myself think better of Saserna’s rule, which is that for each jugerum it suffices to provide four days work of one hand.  Yet, if this was a good rule on Saserna’s farm in Gaul, it might not apply on a mountain farm in Liguria.  In fine you will best determine what number of slaves and what other equipment you will require if you diligently consider three things, that is to say, what kind of farms are there in your neighbourhood, how large are they, and how many hands are engaged in cultivating them, and you should add to or subtract from that number in proportion as you take up more or less work.  For nature gave us two schools of agriculture, which are experience and imitation.  The most ancient farmers established many principles by experiment and their descendants for the most part have simply imitated them.  We should do both these things:  imitate others and on our own account make experiments, following always some principle, not chance:[79] thus we might work our trees deeper or not so deep as others do to see what the effect would be.  It was with such intelligent curiosity that some farmers first cultivated their vines a second and a third time, and deferred grafting the figs from spring to summer.”

Of draught animals

XIX.  In respect of those instruments of agriculture which are called inarticulate, Saserna says that two yokes of oxen will be enough for two hundred jugera of arable land, while Cato prescribes three yokes for two hundred and forty jugera in olives:  thus if Saserna is correct, one yoke of oxen is required for every hundred jugera, but if Cato is correct a yoke is needed for every eighty jugera.  My opinion is that neither of these standards is appropriate for all kinds of land, but each for some kind:  for some land is easy and some difficult to plough, and oxen are unable to break up some land except by great effort and often they leave the ploughshare in the furrow broken from the beam:  wherefore in this respect we should observe a triple rule on every farm, when we are new to it, namely:  find out the practice of the last owner; that of the neighbours, and make some experiments of our own.

“Cato adds,” resumed Scrofa, “that on his olive farm there are required three asses to haul out the manure and one to turn the mill, and on his hundred jugera vineyard a yoke of oxen and a pair of asses for the manure, and an ass for the wine press.”