inclinations in all regards so long as the day’s work was not obstructed and good order was undisturbed.  They had of course everywhere and at all times an interest in the multiplication of their slaves as well as the increase of their industrial aptitudes.  Thus William Lee wrote in 1778 concerning his plantation in Virginia:  “I wish particular attention may be paid to rearing young negroes, and taking care of those grown up, that the number may be increased as much as possible; also putting several of the most promising and ingenious lads apprentices to different trades, such as carpenters, coopers, wheelwrights, sawyers, shipwrights, bricklayers, plasterers, shoemakers and blacksmiths; some women should also be taught to weave."[6]

[Footnote 4:  Review of the Slave Question (Richmond, 1833), p. 17.]

[Footnote 5:  See above, p. 272.]

[Footnote 6:  W.C.  Ford, ed., Letters of William Lee (Brooklyn, 1891), II, 363, 364.]

But even if masters had stimulated breeding on occasion, that would have created but a partial and one-sided relationship between cost of production and market price.  To make the connection complete it would have been requisite for them to check slave breeding when prices were low; and even the abolitionists, it seems, made no assertion to that effect.  No, the market might decline indefinitely without putting an appreciable check upon the birth rate; and the master had virtually no choice but to rear every child in his possession.  The cost of production, therefore, could not serve as a nether limit for slave prices at any time.

An upper limit to the price range was normally fixed by the reckoning of a slave’s prospective earnings above the cost of his maintenance.  The slave may here be likened to a mine operated by a corporation leasing the property.  The slave’s claim to his maintenance represents the prior claim of the land-owner to his rent; the master’s claim to the annual surplus represents the equity of the stockholders in the corporation.  But the ore will some day be exhausted and the dividends cease.  Purchasers of the stock should accordingly consider amortization and pay only such price as will be covered by the discounted value of the prospective dividends during the life of the mine.  The price of the output fluctuates, however, and the rate of any year’s earnings can only be conjectured.  Precise reckoning is therefore impracticable, and the stock will rise and fall in the market in response to the play of conjectures as to the present value of the total future earnings applicable to dividends.  So also a planter entering the slave market might have reckoned in advance the prospect of working life which a slave of given age would have, and the average earnings above maintenance which might be expected from his labor.  By discounting each of those annual returns at the prevailing rate of interest to determine their present values, and adding up the resulting sums, he would ascertain the