29th November, 1928
PERSONAL AND CONFIDENTIAL
(Due to arrive Canberra 28.12.28)
My dear P.M.,
I enclose letter from Sir Eric Geddes , which he has asked me to transmit to you. He has also sent me a copy, and I think I may add a few points to elucidate further what he has in mind.
The development and progressive improvement of passenger and freight carrying aeroplanes in the post-war period has been such that the weight of useful load carried per horse power developed by the engines has increased with each new machine-and if this rate of improvement is maintained, the time when civil flying will be able to proceed without a subsidy is in sight.
As Sir Eric Geddes says, their depreciation (or obsolescence) is provided for at the rate of 25%-i.e. new machines each four years, which he calls a 'generation'. So that the 'three or four generations' that he mentions means 12 or 16 years. In conversation with me, he said 'probably 10 years'.
The route that he has in mind is Singapore-Darwin. Major Brearley  (whom I have seen a good deal of while he has been here) is, of course, anxious that the route should be Singapore-Broome, so that he can carry the mails on from Broome to Perth and Adelaide.
I have arranged a meeting between Major Brearley and Sir Eric Geddes, and also between Brearley and Sir Alan Anderson , and possibly something may develop out of them.
I have also had Brearley and Sir George Lawson-Johnston  (Chairman of Bovril) to lunch, so that the latter could arrange now with Brearley to go by air from Perth to Broome in June next and thence by special machine to Wyndham and around and about their cattle country near Wave Hill and Victoria Downs in North Australia-in connection with the scheme that Sir Charles Nathan  initiated when he was here.
I am, Yours sincerely R.G. CASEY