ARTICLE V. 



A SEARCH FOR FLUCTUATIONS IN THE SUN'S THERMAL RADIATION THROUGH 

 THEIR INFLUENCE ON TERRESTRIAL TEMPERATURE. 



By Simon Newcomb. 



(Read October 4, 1907.) 



PREFATORY NOTE. 



The purpose of the following study is two-fold. The subject of periodicity in 

 meteorological phenomena, and its relation to the sun, is prominent in scientific liter- 

 ature ; and the author desired to treat it by methods different from the usual ones. 

 He also wishes to submit to the courteous consideration of meteorologists the question 

 whether the methods here developed can not be advantageously used in other branches 

 of their science. 



The work has been carried through under the auspices of the Carnegie Institu- 

 tion, the Trustees of which have enabled the author to avail himself of the necessary 

 appliances, facilities, and computing assistance. Acknowledgment is also due to the 

 U. S. Weather Bureau, the Chief of which has placed at the author's disposal, without 

 restriction, the rich body of material contained in its records, as well as the printed 

 collections in its library ; and to the Director of the Deutsche Seewarte of Hamburg for 

 the courteous transmission of unpublished material. 



ANALYTICAL TABLE OF CONTENTS. 



Introduction : — Review of the field ; — general principle of the methods adopted ; — necessity 

 for a criterion for distinguishing between fluctuations of temperature proceeding from local 

 causes and from general causes common to the entire globe. Pp. 311-315. 



CHAPTER I. 



Methods of Investigating Fluctuating Quantities. 

 § 1. Fluctuations in a fixed period. The period being supposed known, the amplitude of the depart- 

 ure at any time maj' be expressed in a Fourier series of v^ich the coefficients can be deter- 

 mined by the method of least squares. Pp. 315-317. 

 A. P. a— XXI. QQ. 13, 1. '08. 309 



