Schedule of Classification 



4250 Electric Radiations. General 481 



4270 Various Radiations ... 481 



Le Bon's Dark Light ... 481 



4275 Radioactivity (radium, etc.). 481-482 



Radium Radiations ... 482 



Uranium ... ... ... 482 



Physiological Optics. (See also 

 Physiology.) 



4400 General ..." ... 482-485 



Optical Illusions ... 483-484 



Optical Phenomena ... 484 



Vision 484-485 



4410 Construction and Dioptrics 

 of the Eye. (See also 

 Physiology 3711.) 485-486 



Construction 485 



Dioptrics 485-486 



4420 Movements of the Eye. Ac- 

 commodation. (See also 

 Physiology 3715, 3740.) 486-487 

 Movements of the Eye ... 486 

 Accommodation . . . 486-487 



4430 Defects of the Eye arid their 

 Correction. Short Sight, 

 Astigmatism, Irradia- 

 tion, etc. ... 487-490 

 Astigmatism ... 487-488 



Irradiation 488 



Short Sight ... 488-489 



Spectacles 489 



Lenses 489 



4440 Binocular Vision (Magnitude 

 and Distance of Objects. 

 Relief.) (See also 3090 ; 

 Physiology 3745.) 490-493 



Binocular Vision ... ... 490 



Distance 491 



Magnitude 491 



Stereoscopic Vision 492-493 



4450 Colour Vision. Subjective 

 Colours. Colour Blind- 

 ness. (See also Physio- 

 logy 3735.) ... 493-500 

 Colour Vision ... 493-498 



Colour Mixture 494 



Colours 495-497 



Complementary Colours 495 

 Primary Colours ... 496 

 Spectral Colours 496-497 

 Rotating Discs, Experi- 

 ments 497 



Spectrum Top ... 497-498 



Theory 498 



Subjective Colours 498-499 



Coloured Shadows ... 499 



Contrast 499 



Colour Blindness . . . 499-500 



4455 Visual Acuity ... 500-501 



4460 Phenomena within the Eye 501-503 



After -Images ... ... 501 



PAGE 



Haidinger's Brushes ... 502 

 4470 Instruments connected with 



Physiological Optics 503-504 



For ELECTRICITY AND MAG- 

 NETISM, 4900 to 6850 see Part II. 



VIBRATION AND SOUND. 

 8990 General 505 



Kinematics of Vibrations and Wave- 

 Motions. 



9000 General 505-506 



9010 Analysis and Synthesis of 



Periodic Motions 506-507 



Lissajous's Figures 506-507 



Apparatus ... 506-507 



9020 Methods of Maintaining, Ob- 

 serving and Measuring 

 Vibrations. (For Radio- 

 phone see 4200.) 507-509 

 Manometric Flames . . . 507 



Vibrations 508-509 



Heated Metals, Vibra- 

 tions : Trevelyan's Ap- 

 paratus ... ... ... 508 



9030 Methods of Exhibiting and 

 Illustrating the Pheno- 

 mena of Wave-Motion 509 

 Wave- Apparatus ... ... 509 



9040 Reflection and Refraction of 



Waves. (See also 9220.) 509-510 

 Reflection ... 509-510 



9050 Interference, Diffraction, and 

 Scattering of Waves. 

 Huygens's Principle ... 510 

 Huygens's Principle ... 510 



Vibrations. 

 9100 General. (See also Mechanics 



3220.) 510-512 



Musical Sand 511 



Production of Sound ... 511 



Vibrations 511-512 



9105 Mechanical Action of Vibra- 

 tions (Acoustic Attrac- 

 tion.) 512-513 



Acoustic Attraction 512-513 



9110 Vibrations of Strings and 



Rods. Curved Rods 513-516 



Strings 513-515 



Wires 514-515 



Rods 515 



Curved Rods ... 515-516 



Tuning-Forks. (See also 



9460.) 515-516 



9120 Vibrations of Membranes 

 and Plates. Curved 

 Plates. Bells ... 516-519 



Membranes ... 516-517 



Plates 517-518 



