24 THE POPULAR SCIENCE MONTHLY. 



start out to obtain a knowledge of the world by visiting its different 

 portions. 



But it was soon found that many never succeeded in getting far 

 away from home. It is true that there were those who, untrammeled 

 by tradition, j>recedent, or authority, made bold excursions into the 

 regions of the unknown, and returned richly laden with spoils, but 

 these were the few ; the many were found to require guidance and 

 support for some time before they became able to carry on explora- 

 tions on their own account. 



The underlying principle of the new method was correct and must 

 survive, but it was a mistake to give it universal and unrestricted ap- 

 plication. The earlier and indeed much of the later instruction in 

 physical laboratories was tinctured with this error. 



By many we were advised that the proper course to pursue was to 

 put into the hands of the student who, in many instances, had little or 

 no previous knowledge of the subject, a few pieces of simple appara- 

 tus and expect him to rediscover for himself principles of physical 

 science which, although now commonplace, were at one time as com- 

 pletely surrounded by difficulties to the human mind as are now, for 

 instance, the principles of the dissipation of energy and the vortex 

 theory of atoms. 



The result of the crude experiments of the student was often to 

 disprove the law which he was expected to establish ; for he lacked 

 that knowledge and training which would enable him to take into con- 

 sideration the influence of secondary causes and conditions, and to 

 determine or properly interpret the errors of experiment. Something 

 was gained, it is true, in the way of familiarity with the methods of 

 manipulation, but very little in the acquisition of real knowledge. 



Even if this method of instruction be made reasonably successful, 

 the actual information concerning natural laws which the student ob- 

 tains must be largely superficial, often erroneous, and the rate of acqui- 

 sition extremely slow. Far better would, it be for him to begin his so- 

 called practical study of the subject after becoming tolerably familiar 

 with its general outlines and prominent features through the study of 

 some reliable text-book, and especially after having armed and equipped 

 himself with such a training in mathematics as will enable him to dis- 

 cuss understandingly the results which he obtains, to consider the limi- 

 tations to which they are subjected, and the influence which has been 

 exerted upon them by errors of various kinds. 



In this matter, as with most others, we are likely to fall into ex- 

 treme views. Some of us maintain that experiment alone is the key, 

 by the use of which Nature's mysteries are to be explored, and we 

 fortify our belief by pointing to Faraday, the greatest experimental 

 philosopher the world has yet produced. We forget that Faraday 

 was ignorant only of the outward, conventional symbols of mathe- 

 matical reasoning, and that one of the greatest works on mathematical 



