It is Always rather risky to ask old people to talk about what things were like when they were young. Having turned on the tap you may not see how to turn it off again. Fortunately there is a circumstance which keeps this trouble under control. Old people remember a lot of things when there is no call for them to do so but seldom when there is. That is the reason why I have written down most of what I can say for this lecture.

I cannot attempt to give a complete or an objective picture of aeronautical science when I started thinking about it. The best I can do is to describe a few of the things which happened to me in those days to try to convey some picture of our primitive ideas.