This paper proposes a radial model of scientific experimental development. I shall support the model with reference to the history of modern electrical experiments in the 18th century. After a brief review of the literature on experimentation, I first analyze the typical structure of experimentation, which consists of the background ideas of experiment, the experimental model and the material realization of the model. Next, I specify 〞the prototypical experiment〞 and 〞the descended experiment〞 and explore the descendent phenomena by juxapositioning the structure of the prototypical experiment against that of the descended one. Then, I discern eight types of descendent relations. Different relations between a prototypical experiment and different descended experiments cause the developmental pattern of experiments to appear radial. Finally, I show that the history of modern electrical experiments fits very well the radial model.