The assistance to an infant industry or a depressed industry is reasonable only if it will thrive within a short time without protection. In every case the demand for protection is on behalf of sectional and not national interests, however much it may be wrapped up in fine words. The cost of the protection is then more precisely known, and public attention focused on the need for its continuance. The quota method acts like the safety-valve in the protective engine, adjusted to blow off steam when the pressure has reached a certain stage, and at the same time it guarantees a margin of protection to home producers. Import boards are a form of protection which at present have merely an academic interest in this country, but it is quite possible that in the future they may become practical politics.