Vi CONTENTS. 



Page 

 XII. Measurement of the Strength of Telephone Currents. By 



Charles R. Cross and James Page 248 



XIII. Experiments with the Thermal Telephone. By Charles R. 



Cross 257 



XIV. Early Experiments in Telegraphing Sound. By Edward 



C. Pickering 262 



XV. Atmospheric Refraction. Part I. By Edward C. Pick- 

 ering 268 



XVI. Atmospheric Refraction. Part II. By Edward C Pick- 

 ering 286 



XVII. A New Form of Polarimeter. By Edward C. Pickering 294 



XVIII. A New Logical Machine. By Allan Marquand, Ph. D. 303 



XIX. On the Capitalization of Land in Early Society. By 



Denman W. Ross, Ph. D 308 



XX. Observations of Variable Stars in 1885. By Edward C. 



Pickering ^^^ 



XXI. On the Methods of Study of Thunder- Storms. By W. M. 



Davis 



336 



XXII. The Dynamic Action of an Electric Current. By Ham- 

 mond Vinton Hayes 348 



XXTII. On the Conditions that determine the Length of the Spectrum. 



By Amos E. Dolbear 361 



XXIV. Contributions to American Botany. By As A Gray ... 363 



XXV. Contributions to American Botany. By Sereno Watson 414 



XXVI. Notes on Arctic Algce ; based principally on Collections 

 made at Ungava Bay by Mr. L. M. Turner. By W. G. 

 Farlow *^^ 



XXVII. On the Crystalline Structure of Iron Meteorites. By Oliver 



Whipple Huntington '*'^ 



XXVin. Notes on Equal Temperament and the Character of Musical 



Keys. By Charles R. Cross 



499 



