Geoff Lewis has spent many years in most branches of engineering including: motor vehicles, aeronautical, communication, telecommunication, production – as an engineer, teacher, lecturer, technical author. Geoff has a keen interest in environmental engineering including hydropower generated inventions. He has written on most of the above subjects, including 10 books, many journal articles and given public lectures. Geoff has long appreciated that knowledge is never wasted and that learning is a life long adventure. He has been told on many occasions that he has the ability to express complex concepts in a fairly easily understandable manner – at least this attribute is at the back of his mind when writing.