If you don't know it already, there is a revised edition of this book (1970).
I don't know where you are based so I've got a few possibilities for you.
The Library and Information Service of Western Australia has a for loan copy of the 1957 edition. It is currently out on loan and has another requestee awaiting its return. Its call number is 365.3 JOH and when in can be found in the 1st Floor Stacks.
The State Library of Tasmania has most copies (2x1970) (1x1957). These are all reference only copies (i.e. not for loan). The 1957 copy is held in the Tasmaniana stack at TL365.3 as is one of the 1970 copies at TL365.3 JOH. The other 1970 copy is held in the State Reference Stack at 365.3 JOH.
The State Library of South Australia also a reference library has a copy of the 1970 edition at 365.3 J71 with the 1957 edition in storage at 365.3 J71. This 1957 copy can be requested for reading. As with the State Library of Tasmania neither of these copies is for loan.
The State Library of Victoria has a copy of the 1957 edition in the main library with a note stack - call slip. I don't know what their lending policy is.
If none of these libraries is in your state nil desperandum.
1. Check with your own state library to see whether it has a copy.
2. If it doesn't there may be a library within your state which also holds it and your state library will let you know which one it is.
3. If that's a no goer, ask if the state library can arrange an interlibrary loan for you. For instance they might arrange for the copy from Perth to come across ... eventually.
If you are from the ACT, the National Library does not have a copy but one of the other libraries might.
If you are intent on having your own copy then you will need to contact an antiquarian bookseller. You will find many in your local telephone book and on the Internet.