FBI agents are not paid in hourly wages, they are paid through the federal government system GS ratings which provides agents an annual salary rating for years served.
The tariff of the United States, like all actual protective tariffs, is partly revenue and partly protective, its original purpose of yielding revenue having been subordinated to that of giving protection, until it may now be best described as a protective tariff yielding incidental revenue.
A tariff is a tax on imports or exports (an international trade tariff). In other languages and very occasionally in English, tariff or its equivalent may also be used to describe any list of prices (electrical tariff, etc.). customs duty or due is the indirect tax levied on the import or export of goods in international trade. In economic sense, a duty is also a kind of consumption tax.