iv 
CONTENTS 
PAGE 
A New Proof of a Theorem Due to Schoenflies By J. R. Kline 529 
On the Structure of Finite Continuous Groups with Exceptionae Trans- 
formations By S. D. Zeldin 541 
Motion on a Surface for Any Positional Field of Force. .By Joseph Lipka. 621 
Seminvariants of a General System of Linear Homogeneous Differential 
Equations By E. B. Stouffer 645 
The Permanent Gravitational Field in the Einstein Theory 
By L. P. Eisenhart 678 
An Application of the Porism of Four Tangents of a Twisted Cubic 
By J. H. McDonald 702 
STATISTICS 
On the Rate of Growth of the Population of the United States since 1790 
and Its Mathematical Representation 
By Raymond Pearl and Lowell J. Reed 275 
On a Single Numerical Index of the Age Distribution of a Population .... 
By Raymond Pearl 427 
A Simplified Method for the Statistical Interpretation of Experimental 
Data By George A. Linhart 682 
A Critical Study of Fertilizer Experiments 
By C. B. Lipman and G. A. Linhart 684 
ASTRONOMY 
A New Method of Determining the Solar Constant of Radiation 
By C. G. Abbot 4 
The Larger Opportunities for Research on the Relations of Solar and 
Terrestrial Relation By C.G. Abbot 82 
A Note on a Simple Device for Increasing the Photographic Power of 
Large Telescopes By Harlow Shapley 127 
Studies of Magnitudes in Star Clusters, XI. Frequency Curves of the 
Absolute Magnitude and Color Index for 1152 Giant Stars 
By Harlow Shapley 293 
Report on the Organization of the International Astronomical Union. . . . 
By W. W. Campbell and Joel Stebbins 349 
Studies of Magnitudes in Star Clusters, XII. Summary of a Photometric 
Investigation of the Globular System Messier 3 
By Harlow Shapley and Helen N. Davis 486 
New Observations on the Variability of the Sun By C. G. Abbot 674 
PHYSICS 
An Example of Torsional Viscous Retrogression By Carl Barus 2 
The Intensities of X-Rays of the L-SeriEs, II. The Critical Poten- 
tials OF THE Platinum Lines By D. L. Webster 26 
Spectra of Explosions By J. A. Anderson 42 
The Torsional Magnetic Energy Absorption of an Iron Conductor 
By Carl Barus 59 
A Study of Absorption Spectra with the Electric Furnace 
By A rthur S. King 63 
A Study of the Effect of a Magnetic Field on Electric Furnace Spectra . . 
By Arthur S. King 65 
A Statistical Method for Studying the Radiations from Radioactive Sub- 
stances AND THE X-RaYS and ITS APPLICATION TO SOME 7-Ray PROBLEMS . . 
By Alois F. Kovarik 105 
