8th March, 1928
PERSONAL AND CONFIDENTIAL
My dear P.M.,
AIR DEFENCES OF AUSTRALIA
I enclose 'Times' announcement of Sir John Salmond's mission to Australia. 
A Senior Officer of the Staff of the Imperial Defence College, of whom Hankey  has a high opinion (but whom I am asked to keep anonymous), writes privately to Hankey enclosing a memorandum on the subject of Sir John Salmond's visit, of which, as you will see, he does not approve.
Even admitting that there exists no accepted body of doctrine as to the exact function and responsibility that the Air can take in coast defence, it seems to me that this officer assumes too low an order of intelligence and balance in Sir John Salmond. 
However, it is a point of view with regard to which you will no doubt wish the Minister for Defence  to be aware.
I am, Yours sincerely, R.G. CASEY