The Author endeavours to indicate briefly the growth of flying—boats from their inception to the present day and to forecast their probable line of development in the future. It is shown that our present achievement has been arrived at after the comparatively short period of twenty—five years and an attempt has been made to indicate the type of flying—boat which might normally be expected to mature within the next decade.

The water characteristics of a present—day hull are discussed and typical curves are included giving the resistance, attitude and the effect of applied moment for a flying—boat of approximately 40,000lb., all—up weight.

Before proceeding to a detailed investigation into a particular case of a flying—boat of the future, the Author briefly describes the progress which has been made with regard to the engines and compares the relative advantages of the compression—ignition engine and the petrol engine.Reasons are given why the petrol engine still tends to retain its supremacy.

For the future development the Author has taken the particular case of a flying—boat of 300,000lb. all—up weight and has attempted to analyse the probable structure weight of such an aircraft and what could reasonably be expected in the way of pay load and performance.The general conclusions are that the construction of such a boat would be possible, its structure weight by means of an increased wing loading could be maintained at the present—day figure and that its performance would materially increase.