INTRODUCTORY LECTURE ON EXPERIMENTAL PHYSICS. 247 



There is no more powerful method for introducing knowledge into the 

 mind than that of presenting it in as many different ways as we can. When 

 the ideas, after entering through different gateways, effect a junction in the 

 citadel of the mind, the position they occupy becomes impregnable. Opticians 

 tell us that the mental combination of the views of an object which we obtain 

 from stations no further apart than our two eyes is sufficient to produce in 

 our minds an impression of the solidity of the object seen ; and we find that 

 this impression is produced even when we are aware that we are really looking 

 at two flat pictures placed in a stereoscope. It is therefore natural to expect that 

 the knowledge of physical science obtained by the combined use of mathematical 

 analysis and experimental research will be of a more solid, available, and enduring 

 kind than that possessed by the mere mathematician or the mere experimenter. 



But what will be the effect on the University, if men pursuing that course 

 of reading which has produced so many distinguished Wranglers, turn aside to 

 work experiments ? Will not their attendance at the Laboratory count not 

 merely as time withdrawn from their more legitimate studies, but as the intro- 

 duction of a disturbing element, tainting their mathematical conceptions with 

 material imagery, and sapping their faith in the formulae of the textbooks ? 

 Besides this, we have already heard complaints of the undue extension of our 

 studies, and of the strain put upon our questionists by the weight of learning 

 which they try to carry with them into the Senate-House. If we now ask 

 them to get up their subjects not only by books and writing, but at the same 

 time by observation and manipulation, will they not break down altogether? 

 The Physical Laboratory, we are told, may perhaps be useful to those who 

 are going out in Natural Science, and who do not take in Mathematics, but to 

 attempt to combine both kinds of study during the time of residence at the 

 University is more than one mind can bear. 



No doubt there is some reason for this feeling. Many of us have already 

 overcome the initial difficulties of mathematical training. When we now go on 

 with our study, we feel that it requires exertion and involves fatigue, but we 

 are confident that if we only work hard our progress will be certain. 



Some of us, on the other hand, may have had some experience of the 

 routine of experimental work. As soon as we can read scales, observe times, 

 focus telescopes, and so on, this kind of work ceases to require any great 

 mental effort. We may perhaps tire our eyes and weary our backs, but we do 

 not greatly fatigue our minds. 



