30 MICHIGAN ACADEMY OF SCIENCE. 



admit of precise quantitative statement. The student of phvsiis finds 

 a subject which busies itself with the reason of thing,s. Its business 

 is to account for natural phenomena in the simplest possible manner. 

 Causal relations are among the most prominent of those studied. An 

 earnest study of physics, especially by the laboratory method, disin- 

 clines the student to rest on the authority of a text-book. He learns to 

 try all things and to hold fast that which is good. Without losing- 

 respect for the opinions of others, he learns to discriminate for him- 

 self. In the laboratory he has ample opportunity to form independent 

 judgments. His work contributes to the making of a man who not 

 only knows but who does. The student in practical physics "must 

 acquire a certain technique, a deftness and certainty of touch, an ability 

 to handle and adjust apparatus, which, however small it may seem to 

 be in itself, forms one of the characteristic ditferences between the 

 civilized man and the savage." There is a close but almost indefinable 

 relationship between manual and mental training. Manual dexterity 

 begets mental agility. The refinement of the mind expresses itself in 

 the refinement of manipulative skill. Trained fingers and a trained 

 mind give the possessor a double claim on public appreciation. The 

 artistic instinct and artistic appreciation do not make an artist. To 

 these must be added dexterity with the brush, the pliable fingers, the 

 mallet and chisel. Musical feeling expresses itself at the very finger 

 tips. The hand is often as good an index of character as the face. The 

 combined mental and manual skill cultivated in physical manipulation 

 is no mean reward for the time devoted to it. 



Physics has also other and perhaps higher motives. It considers 

 not only the things which are seen, but still more the things that are 

 not seen. If it has to do with many-sided matter, it has also to do with 

 multiform energy. The most important and most facinating phenomena 

 of physics are not the things one can see, but the invisible things that 

 one apprehends only by the use of the imaginative faculty. It thus 

 happens that the serious study of physics cultivates in no small degree 

 the power of imagination. Force is invisible, though matter is its 

 medium; energy is invisible, and so difficult is its apprehension that 

 even cultivated men fail to distinguish between it and force. An elec- 

 tromagnet is a simple electric device; but when we contemplate its 

 attendant magnetic field with its invisible magnetic lines in the in- 

 visible ether, and try to picture to ourselves hoAV energy is transmitted 

 and transmuted through the agency of this invisible magnetic halo 

 of gossamer threads, the imagination is taxed to its utmost capacity. 

 Consider further the fairy land of light, the audience hall of sound, 

 the seething caldron of solar heat, or the ai>palling chill of liquid air, 

 of interstellar space, or of the deathlike immobility of the absolute zero 

 of temperature. Follow if you can the flow of radiant energy with the 

 speed of light through boundless space, and tell us whether the Al- 

 mighty, who let it fly, corrals it again and holds it in leash in some un- 

 known rendezvous on the boundary of the infinite. The discoveries of 

 physics outrun even the imaginations of men. When the first report 

 of Roentgen rays was bruited abroad we received it with incredulity. 

 That an exhausted glass tube, excited with electricity, should render 

 visible the bones of a living man, and should enable one to see the 

 pulsating heart, was a unique fact lying beyond the realm of fancy 



