The objective of this paper is to develop a theory for analysing the practice of representing the world with visualizations in the form of different images and the scientific gaze that renders these images meaningful. These images are often combined with text, since the natural sciences are lexivisual practices. For natural scientists these visual and lexivisual representations appear totally unproblematic. Scientific representations can be many kinds of pictures, graphs, tables or diagrams and are seen as vehicles of knowledge; in their concrete and tangible form we call them images but they can also be displayed, screened and projected. I will not directly deal with mental images or conceptions of the world, only as one way to understand what renders the tangible images meaningful. But of course, the conflict between a culturalistic and a natural scientific conception of the world runs through this paper, as the empirical material is natural scientific and the analysis is culturalistic.