The Act of 1660 established two rules applicable to the Plantation trade, which were deemed of the highest importance to the country: first, that the whole trade of the Plantations should be carried on in “British” ships only; and secondly, that the principal productions of these Plantations should be allowed to be exported only to the mother country, or some other Plantation. A third general rule was introduced, a year or two later, by the Act of 15 Car. II., cap. 7, sect. 6, viz., that no goods of the produce of Europe should be imported into any of the Plantations in Asia, Africa, or America (except Tangier[49]), in any vessels whatsoever, but such as were _bonâ fide_ and without fraud laden and shipped in England, Wales, or the town of Berwick-upon-Tweed, in English-built vessels.[50] In the year 1825, on the general consolidation of the Customs Laws, the above limitations of the right of exportation were removed, and the law with regard to the _Plantation trade_ was placed nearly on the footing on which it stood in 1847. In fact, the further consolidations of 1833 and 1845 made little change in the previous regulations. With regard to _Rule 3_, viz., that goods, the produce of Europe, were only to be imported into the colonies from the United Kingdom, this was subject, originally, to a few exceptions: thus, salt might be taken to the fisheries from any port of Europe; and wines of Madeira and the Azores might be imported thence, &c. A relaxation of the rule was first made in favour of Irish linens, various subsequent alterations having been introduced, till at length, in 1825, the law with reference to such importations was placed on nearly the same footing as prevailed in 1847; that is to say, the importation and exportation of all classes of goods into or from the “Free Ports” in different colonies were, generally, legalised, subject to certain prohibitions against the importation of particular articles, some of which were afterwards removed, while others (_e.g._ those against pirated books, counterfeit coin, &c., and the restrictions on gunpowder, arms, &c.) remained. A tariff of differential duties on foreign goods, of which duties one-tenth (subsequently increased to one-fourth) was to be remitted, when the goods were imported through an English warehouse, was, at the same date, enforced. The principle of this tariff and of the practice of remission were retained; but legislation was constantly effecting small changes, to meet the wishes or, rather, the demands of colonial legislatures which perhaps, naturally, looked only to their own interests. Such may be taken as the intermediate history of the Navigation Law as it affected the Plantation or Colonial trade. [Sidenote: First infringement of the principle of confining the American trade to British vessels.]