Suppose, for example, that 10 yards of broad cloth cost in England as much labour as 15 yards of linen, and in Germany as much as 20. If England sends 10 yards of broad cloth to Germany, and is able to exchange them for linen according to the German cost of production, she will get 20 yards of linen, with a quantity of labour with which she could not have produced more than 15; and will gain, therefore, 5 yards on every 15, or 33-1/3 per cent. But in this case Germany would obtain only 10 yards of cloth for 20 of linen. Now, 10 yards of cloth cost exactly the same quantity of labour in Germany as 20 of linen; Germany, therefore, derives no advantage from the trade, more than she would possess if it did not exist. So, on the other hand, if Germany sends 15 yards of linen to England, and finding the relative value of the two articles in that country determined by the English costs of production, is enabled to purchase with 35 yards of linen 10 yards of cloth; Germany now gains 5 yards, just as England did before,--for with 15 yards of linen she purchases 10 yards of cloth, when to produce these 10 yards she must have employed as much labour as would have enabled her to produce 20 yards of linen. But in this case England would gain nothing: she would only obtain, for her 10 yards of cloth, 15 yards of linen, which is exactly the comparative cost at which she could have produced them. This, which was not an error, but a mere oversight of Mr. Ricardo, arising from his having left the question of the division of the advantage entirely unnoticed, was first corrected in the third edition of Mr. Mill's _Elements of Political Economy_. It can hardly, however, be said that Mr. Mill has prosecuted the inquiry any further; which, indeed, would have been quite as inconsistent with the nature of his plan as of Mr. Ricardo's. 1. When the trade is established between the two countries, the two commodities will exchange for each other at the same rate of interchange in both countries--bating the cost of carriage, of which, for the present, it will be more convenient to omit the consideration. Supposing, therefore, for the sake of argument, that the carriage of the commodities from one country to another could be effected without labour and without cost, no sooner would the trade be opened than, it is self-evident, the value of the two commodities, estimated in each other, would come to a level in both countries. If we knew what this level would be, we should know in what proportion the two countries would share the advantage of the trade.