Overview

In his lectures Faraday communicated not only through words but by his deft manipulation of nature. As a virtuoso he could make operations of nature manifest before the audience's eyes. His audience thus both heard about the laws of nature and also saw them in action. It is significant that in an early letter Faraday had placed the power of the eye far above that of the ear in conveying ideas clearly to the mind. Thus observable experiments played a central role in Faraday's didactic repertoire. For the audience the immediacy of this experience proved one of the most potent aspects of Faraday's lectures. ^[1]

Geoffrey Cantor

Having a supporting cast of visual aids has many advantages, but almost as many pitfalls. One major advantage is that a strong supporting cast of projected slides, demonstrations, and pass-arounds can convey images, sounds, textures, tastes, and smells much more effectively than spoken words can. With a projected slide, for example, you can precisely and efficiently show the arrangement of a complex image such as the gas turbine engine depicted in Figure 4-1. Moreover, in a demonstration, you can provide the audience with the simulated roar of the Parasaurolophus dinosaur. ^[2] In addition, with passarounds, you can allow audiences to feel a snake's skin, to experience the garlic taste of dimethyl sulfoxide, or to sniff the odor of acetone (which on a patient's breath is a symptom of diabetes). By incorporating a supporting cast of visual aids, you allow the...