i>.V SCIEXCE TEACHING L\ LABORATORIES 185 



briefly, is that we 'can teach him systematically the art of 

 measurement. We cannot give him the hunger for knowledge, 

 the acute logical discrimination, nor the imaginative faculty 

 required for research ; but we can teach him how to ascertain 

 and record facts accurately ; we can bring home to him the truth 

 that no scientific knowledge is definite except that based on the 

 numerical comparison which we call measurement ; we can teach 

 him the best modes of making that comparison in respect of a 

 vast number of magnitudes, and in teaching this we shall teach 

 him to use his hands and eyes. This practical teaching gives 

 clear conceptions to the minds of many who receive a verbal 

 definition as a mere string of dead words. I should be glad if it 

 were generally proclaimed that the elementary training in all our 

 science laboratories should be a training in the art of measure- 

 ment. I wish that the classes were called measurement classes. 

 Then a student of ordinary intelligence would know that by 

 entering a given class he would learn how to measure those mag- 

 nitudes with which he will have to deal in after life. The 

 attempt to measure them will lead him to consider their nature, 

 and he will approach scientific study in the class-room with a 

 faith in the reality of science which no verbal exhortation will 

 ever give him. You may define the absolute unit of electrical 

 resistance as accurately as you will, and your definition shall 

 affect the average brain to no perceptible extent ; but a young 

 man of very ordinary education and intelligence can learn to 

 measure resistances in ohms, and having learnt this, an ohm 

 becomes a reality to him. Not only does the knowledge he has 

 acquired make him a more valuable assistant to the engineer and 

 contractor, but having acquired a working faith in the existence 

 of ohms, he is prepared to take some trouble to understand the 

 scientific definition. 



Let me again repeat that I am here urging no new thing. I 

 am merely, as I believe, stating the practice of all well-arranged 

 laboratories they are schools of measurement a fact long since 

 recognised by the chemist, but less explicitly recognised in other 

 branches of physical science. The student of heat or light may 

 come to the laboratory thinking vaguely that he is to make 

 experiments and to him an experiment does not imply a 

 measurement. I have heard a young man describe as a very 

 interesting experiment, performed by his teacher, the blowing-up 



