Having arrived at an understanding of how precipitation forms, we can move on to see how it can be measured and the many problems that arise in the attempt to obtain precise data. The importance of measurements was stressed by Leonardo da Vinci when he wrote:

In the above, ‘experiment’ also had the meaning of ‘experience’ in Leonardo's time. What he was saying was what others have said often since, that Aristotle's way of doing ‘science’, by just thinking and talking without looking and testing was not science at all.

Until the late nineteenth century, attempts to measure rain were quite rare, and so each is remarkable and worthy of comment. The next chapter traces the history of these early attempts. Their origins were probably in simple agricultural aids, but in Europe from the seventeenth century onwards there developed a more academic approach, arising from scientific curiosity aided by improving technology. In Chapters 8 to 11, I review the current state of the technology, looking in some detail at how precipitation is measured today with raingauges, radar and satellites.