An illustration of this may be found in the eminently ingenious and eminently erroneous work of Colonel Torrens, called “The Budget.” Colonel Torrens supposes the commercial world to consist of only two countries, equal in wealth and civilisation, which he calls England and Cuba. He supposes that England has peculiar advantages for the production of woollens, and Cuba for that of sugar, and that the cloth of the one, and the sugar of the other, are freely exchanged in proportion to the labour which each has cost. He then supposes Cuba to impose a duty on English cloth, which would of course, to a certain extent, prevent its importation; and he states that the consequence would be, that England would have to send money to Cuba for sugar, until the exportation of money had impoverished England, and its importation had enriched Cuba. Now if Colonel Torrens, instead of hypothetical, had taken real cases, if he had inquired, for instance, into the results of the prohibitive system of France, and had come to the conclusion that that system increases her wealth, the strangeness of such a result would have led him to suspect an error in his facts or in his reasoning. But the strangeness of the result of an imaginary case did not rouse his suspicion. The fact is, that his hypothetical argument is erroneous; and the error consists in his not having taken into account an element essentially incident to his supposed case, namely, the influence of commercial restrictions on the efficiency of labour. If he had taken this element into account, he would have found that Cuba, by her prohibitive system, would diminish the productive power of her labour, and consequently would find it her interest to import from England commodities which she previously produced at home; so that the ultimate result would probably be, rather an export of gold from Cuba than from England. Colonel Torrens’s book always reminds me of the suit of clothes which the Laputa tailor cut on hypothetical data. Unfortunately, however, for the credit of the Laputa artist, Gulliver tried them on, and the error which had slipped into the calculation showed itself in every form of misfit. Happily for Colonel Torrens, and happily for ourselves, we have not tried on his theory.