I get to airports ridiculously early. It’s an uncontrollable urge.

one of my diseases, one of my things in life, is that anything that is secret I try to undo. And so the locks to those filing cabinets represented a challenge to me. How the hell to open them? So I worked and worked on them. There are all kinds of stories about how you can feel the numbers and listen to things and so on. That's true; I understand it very well - for old- 19 fashioned safes. But these had a new design so that nothing would be pushing against the wheels while you were trying them, and none of the old methods would work. I read books by locksmiths, which always say in the beginning how they opened the locks when the safe is under water and the woman in it is drowning or some-thing, and the great locksmith opened the safe. And then in the back they tell you how they do it, and they don't tell you anything sensible. It doesn't sound like they could really open safes that way — like guess the combination on the basis of the psychology of the person who owns it! So I always figured they were keeping the method a secret, and like a kind of disease, I kept working on these things until I found out a few things. First, I found out how big a range you need to open the combination, how close you have to be. And then I invented a system by which you could try all the necessary combinations - 8,000, as it turned out, because the woman DROWNING عزه Books are always telling how the great locksmith opens the safe under water when the woman in it is drowning. 20 you could be within two of every number. And then I worked out a scheme by which I could try numbers without altering a number that I had already set, by correctly moving the wheels, so that I could try all the combinations in eight hours. And then finally I discovered (this took me about two years of researching) that it's easy to take the last two numbers of the combination off the safe if the safe is open. If the drawer was pulled out, you could turn the number and see the bolt go up and play around and find out what number it comes back at, and stuff like that. With a little trickery, you can get the combination off. So I used to practice it like a cardsharp practices cards, you know - all the time. Quicker and quicker and more and more unobtrusively I would come in and talk to some guy. I'd sort of lean against his filing cabinet, and you wouldn't even notice I'm doing any-thing. I'm not doing anything— just playing with the dial, that's all, just playing with the dial. But all the time I was taking the two numbers off! And then I would go back to my office and write the two numbers down, the last two numbers of the three. Now, if you have the last two numbers, it takes just a minute to try for the first number; there's only 20 possibilities, and it's open. OK? It takes about three minutes to open a safe if you know the last two numbers. So I got an excellent reputation for safe-cracking.

Until this time I had never been able to drink whisky. I disliked the flavour intensely. I could not understand how so many of my brother officers were so often calling for a whisky and soda. I liked wine, both red and white, and especially champagne; and on very special occasions I could even drink a small glass of brandy. But this smoky-tasting whisky I had never been able to face. ... Once one got the knack of it, the very repulsion from the flavour developed an attraction of its own; and to this day, although I have always practised true temperance, I have never shrunk when occasion warranted it from the main basic standing refreshment of the white officer in the East.

Have more than one idea on the go at any one time. If it’s a choice between writing a book and doing nothing I will always choose the latter. It’s only if I have an idea for two books that I choose one rather than the other. I ­always have to feel that I’m bunking off from something.

The advice that I would give is try to find something that you like. Try to devote your energies to being very good at it. Try to achieve excellence. Don’t necessarily have as a goal success or getting prizes or whatever, but just doing very good work. And work hard. Keep working at it. Be patient. Realize that you don’t always see the benefits of what you’re doing, short-term. But in the end, the activities that I do, for example, scientific research, can be extremely rewarding. It’s really a very fascinating career.

proud of recognizing that as a scientist, it was not only important to do research and find new things. I also felt a responsibility to apply them for the benefit of society.

I have also benefited from teaching; as I try to explain my views to students with critical and open minds, I find myself continually being challenged to go back and rethink ideas. I now see teaching and research as complementary, mutually reinforcing activities.

At first the research did not seem to be particularly interesting – I carried out a systematic search for processes that might destroy the CFCs in the lower atmosphere, but nothing appeared to affect them. We knew, however, that they would eventually drift to sufficiently high altitudes to be destroyed by solar radiation. The question was not only what destroys them, but more importantly, what the consequences are.

Sherry offered me a list of research options: the one project that intrigued me the most consisted of finding out the environmental fate of certain very inert industrial chemicals – the chlorofluorocarbons (CFCs) – which had been accumulating in the atmosphere and which at that time were thought to have no significant effects on the environment. This project offered me the opportunity to learn a new field – atmospheric chemistry – about which I knew very little; trying to solve a challenging problem appeared to be an excellent way to plunge into a new research area.

It was probably a series of biographies of scientists like Pasteur, or even earlier ones — Leeuwenhoek inventing the microscope and Madame Curie. I forget how many others, but it was really just, for me, a fascination to learn about these great heroes. At that time, of course, they were totally inaccessible, almost non-human, to me. It became very interesting to me.