It was said, however, that the adoption of any other view would restrict the power of the Senate beyond anything that could have been in the contemplation of the framers of the Constitution, in that if machinery provisions of the sort to which I have referred could be made part of a law imposing taxation, then the Senate could not amend such provisions. This consequence may follow but, if so, there are two things to be said about using it as a reason for giving s. 55 an extended operation. The first is that, as appears from Erskine May's Parliamentary Practice (1893) 10th ed., p. 542, the parliamentary convention, upon which ss. 53 to 55 of the Constitution were unquestionably based, prevented the Lords from amending Bills which they received from the Commons dealing with aids and supplies, so as to alter, whether by increase or reduction, the amount of a rate or charge - its duration, mode of assessment, levy, collection, appropriation, or management; or the persons who pay, receive, manage, or control it; or the limits within which it is leviable. The second is that a parliamentary convention has developed in Australia of having separate "tax" Acts and "assessment" Acts which goes beyond what is necessary to avoid invalidity under s. 55, but which is directed to securing to the Senate a wider power of amendment than it would have if tax Acts were themselves to contain the machinery for the assessment, collection and enforcement of tax. This parliamentary practice, therefore, while maintaining and facilitating the observance of s. 53, goes further than the Constitution does by s. 55 to safeguard the position of the Senate in respect of the amendment of laws dealing with taxation. The maintenance of this convention is not, however, any part of the function of the Court and the convention itself affords no ground for departing from the strict construction of s. 55 that has always been adopted.