As in the reign of Charles I., it was therefore towards the development of British fisheries that efforts were first directed. The means taken with this view were twofold: the taxation of imported fish which had been caught by foreigners, and the creation of great fishery associations like those which had been established earlier in the century. The Navigation Act, which was passed a few months after the Restoration, while more oppressive to Dutch commerce and shipping than the Act of 1651, was less stringent in this particular. The measure of the Rump Parliament prohibited the importation or exportation of fish, or its carriage coastways, unless such fish had been caught by subjects. This prohibition was ineffective,[811] and it was now replaced by the imposition of double customs on all kinds of dried or salted fish imported, if caught or brought by vessels other than English.[812] Three years later, the importation of fresh herrings, cod, haddocks, and coal-fish was absolutely prohibited unless they had been taken and imported in vessels certified to be English.[813] With the view of still further promoting the fisheries, the same prohibition was afterwards extended to cured fish and certain other fresh fish,[814] which practically restored the provision of the first Act of 1651. To a large extent these variations were due to the trade rivalries that existed in England, the party which was uppermost at the time forcing the measures that were most in its interest. Besides protective duties and monopolies, more direct means of encouraging the fisheries were tried. The always attractive idea was revived of establishing a great national fishery society, which, on the one hand, would enrich those who supported it with their purse, and on the other hand would increase the prosperity and the power of the country. Simon Smith, who had been the agent of the Royal Fishery Society in the reign of Charles I., lost no time in presenting to the king his two books on the subject, along with a petition in which he dwelt upon the advantages that would accrue to the nation from the labours of such an association.[815] Smith recommended that all the corporations and county towns in the kingdom should conjointly raise a stock to buy hemp and other materials to equip busses, which were to be built at the seaports nearest to them and sent to the fishing at Shetland; and he calculated, after the usual fashion, that each buss would maintain twenty families in work, “breed country youths to be mariners,” and cause many ships to be employed in exporting the herrings and bringing back commodities.