FIG. 
* I 
LIST OF DIAGRAMS 
Energy and Wave-length of Radiation 
PAGE 
2 
t 2 
The Phase Plane ...... 
l8 
3 
The Simple Rotator ...... 
24 
4 
The Magnetic I-H Curve ..... 
34 
5 
(Reproduced from “A Textbook of Intermediate Physics” (Moore), Methuen & Co., Ltd.) 
The Parson Magneton or Ring Electron .... 
40 
6 
Field of a Ring Electron ..... 
4i 
t 7 
The Balmer Series in the Hydrogen Spectrum . 
48 
* 8 
Circular Orbits ....... 
55 
* 9 
Elliptic Orbits ....... 
61 
IO 
Energy Levels ....... 
64 
*n 
Atomic Energy Levels (Bohr and Coster) . 
72 
* 
Table. A Periodic Classification of the Elements 
(Bohr) 
76 
tl2 
Quantization in Space ..... 
84 
f!3 
Spatial Position of Orbital Planes 
85 
14 
Experiments of Gerlach and Stern 
88 
$15 
Ewing’s Model ....... 
119 
§16 
The Single Bond ...... 
124 
§i7 
The Double Bond ...... 
124 
§18 
Optically Active Forms of a Compound 
124 
$19 
Hydrogen Molecule 6 — 60° .... 
129 
$20 
Hydrogen Molecule d = 45 0 .... 
130 
21 
Elliptic Orbit ....... 
138 
22 
Magnetic Tubes for Two Current Circuits . 
142 
23 
Magnetic Tubes to a Dipole . 
161 
24 
Field due to a Small Magnet . . . . 
162 
25 
Moving Magnetic Doublet . 
194 
26 
Normal Zeeman Resolution . . . . 
205 
27 
Zeeman Effect ....... 
206 
28 
Model illustrating the Zeeman Effect 
207 
29 
Energy Levels ....... 
219 
30 
Elliptic Orbit ....... 
259 
* 
Reproduced from “ The Basis of Modern Atomic Theory” (Douglas Clark), Methuen 
v_v L/U. j J—/I/Lv» 
f Reproduced from “Atomic Structure and Spectral Lines” [Sommerfeld), Methuen & 
Co., Ltd. 
X Reproduced from “ Proceedings of Royal Society of Edinburgh,” by permission of the 
Secretary. 
§ Reproduced from “Philosophical Magazine,” by permission of the Editors. 
xiii