The greater part of manufacturers could not afford to retail their own goods so cheap as a vigilant and active shopkeeper, whose sole business it was to buy them by wholesale and to retail them again.

大多数制造商无法像警惕而活跃的店主那样以如此低的价格零售他们自己的商品，店主的唯一业务就是批发购买商品并再次零售。

A smith who has been accustomed to make nails, but whose sole or principal business has not been that of a nailer, can seldom, with his utmost diligence, make more than eight hundred or a thousand nails in a day.

一个习惯于做钉子的铁匠，如果他的唯一或主要业务不是做钉子的，即使他尽最大的努力，也很少能在一天内做超过八百或一千个钉子。