282 THE POPULAR SCIENCE MONTHLY 



is different from understanding them. Merely to go into the fields is not 

 to study botany, and unless we carry that definite aim with us the stroll 

 is much more likely to add to our dumb enjoyment than to extend our 

 knowledge. The eye may be filled while the mind is left untouched ; for 

 it is just when sense is thus completely satisfied that reflection is most 

 likely to lie unstirred. 



The vogue of illustration, as an adjunct of public lecturing, marks 

 such a change of habitual attitude. We go to the lecture, as to the 

 theater, to be entertained, not to be instructed; and are so absorbed in 

 looking that we cease to think. A swift succession of vivid impressions, 

 resplendent in color or palpitating with motion, passes before the gaze. 

 There is as little leisure for reflection as directive stimulation to thought. 

 The senses are stimulated and at last jaded, as picture succeeds picture 

 and topic replaces topic; until, breathless with the dizzying rush of 

 scenes, we are at last tossed back, momentarily bewildered, into normal 

 relations with the world about us. 



Under such conditions the verbal commentary of the lecturer becomes 

 a matter of secondary importance, and we accept a mediocrity of merit, 

 or even a literal incoherence, which would never have been tolerated 

 under the more exacting conditions of the lyceum. Indeed, if the 

 pictures be only chosen skilfully enough the text may be rendered wholly 

 negligible, as the kinetoscopic theater indicates by its elimination. In a 

 word, the speaker has been replaced by the picture-machine, and a cor- 

 responding change in our conceptions of merit has accompanied the sub- 

 stitution. We require better and ever better pictures and promote a race 

 for mechanical perfection. We stimulate the ingenuity of inventors to 

 devise fresh marvels of reproduction; color is added to form, and mo- 

 tion to color ; but still we demand more. The world is ransacked for its 

 treasures of picturesqueness or beauty, and men's brains racked to con- 

 ceive new dramas and burlesques of action. As a result these pictorial 

 and esthetic demands finally supersede the lecturer's original function of 

 interpretation. 



This trend has perhaps been most striking where it has been least 

 justifiable, in connection with the presentation of scientific materials. 

 The change is at least suggested in the subordination of theoretical to 

 experimental and demonstration methods in teaching. The aim of scien- 

 tific instruction is to put the mind in possession of a system of explana- 

 tory concepts. These are necessarily abstract and can not be set forth in 

 the form of concrete examples. There is therefore a danger that atten- 

 tion, detained by its purely picturesque aspects, may recall the demon- 

 stration merely as an impressive spectacle, and thus lose sight of the 

 principles which it illustrates. The use of demonstration methods in the 

 class-room, however, presents less subversion of aim than that of plat- 

 form illustration. The lantern-slide has won a secure place in the tech- 



