184 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1923 



laid out in simple proportion, for if we represent the length of the 

 visible spectrum by one-quarter inch space, then the whole ultra- 



0CTAV23 

 __0_. 



GAMMA KAY3 



FROM R4DIUM 



•icrj 



20. 



TOCsTASURED 



ULTRA VIOLET 



VISIBLE 



INFRA RED 



NEW ELECTRIC 



WAVE REGION I 30. 



FARLIER SHOET 

 ELECTRIC WAVE3 



RADIO 



10. 



I -I 



50. 



WAVE-LENGTH (CM) BOW MEASURED 

 - . -.QOQ.C-QP.QOC/.fc 



,QOp,0_00, OOP, 7_ 



,000,000,018,7 



.PP_0.flQQ.13?. 



.PQP.,001 J 36_. 



.000,038 



.Qop.flra 



CRYSTAL 

 REFLECTION 



, QUANTUM 

 RELATION 



GRATING 



.025 



~A&1 



INTERFEROKETER 



. J»9S2' 



ELECTRICAL 

 RESONANCE 



I JB, OOP ,000. 

 Fig. 5. — Chart of the electromagnetic spectrum 



violet, X ray, and gamma ray spectra are crowded into another one- 

 quarter inch at the left, while on the right the infra-red spectrum 



