¹ I cannot, however, make sense of Mr. MacDonald's remark that “Duty rates may be conceived of under these circumstances, not as a tax to produce revenue, not even mainly as an incentive to manufacture in Canada rather than to import, but simply as one more cost hurdle to be surmounted,” since the sole purpose of the hurdle is to induce the manufacturer to manufacture in Canada, and Mr. MacDonald himself believes that some degree of protection is essential to the survival of production in Canada.