"Rights of every kind, which stand upon the foot of usage, gradually receive new strength in point of light and evidence from the continuance of that usage; as it implieth the tacit consent and approbation of every successive age, in which the usage hath prevailed. But when the prerogative hath not only this tacit approbation of all ages, the present as well as the former on its side, but is recognised, or evidently presupposed, by many Acts of Parliament, I see no legal objection that can be made to it."