CONTENTS. 



Page 

 I. An Investigation of the Errors in Cooling Cuives and Methods 

 for Avoiding these Errors; Also a New Form of Crucible. 

 By H. C. Hayes 1 



II. Determination of the Altitude of Aeroplanes. By R. W. 



WiLLSON 23 



III. The Nature of Volcanic Action. By R. A. Daly .... 45 



IV. The Pegmatites of the Riebeckite-Aegirite Granite of Quincy, 



Alass., U.S.A.; Their Structure, Minerals, and Origin. By 



C. H. Warren and C. Palache 123 



V. The Transition Temperatures of Sodium Chromate as Convenient 

 Fixed Points in Thermometry. By T. W. Richards and 

 G. L. Kelley 169 



VI. (/.) On the Classification of Certain>Eupatoricae ; {II.) Revision 

 of the Genus Barroetea; (III) On some Hitherto Undescribed 

 or Misplaced Composite. By B. L. Robinson 189 



VII. Calanoid Copepoda from the Bermuda Islands. By C. O. 



ESTERLY 217 



VIII. The von Waltenhofen Phenomenon in Soft Iron Rings. By 



L. A. Babbitt 227 



IX. A New Method of Impact Excitation of Undamped Oscillations 

 and their Analysis by means of Braum Tube Oscillographs. By 

 E. L. Chaffee 265 



X. The Wave Potential of a Circular Line of Sources. By A. (J. 



Webster 313 



XI. The Measurement of Hydrostatic Pressures up to 20,000 Kilo- 

 grams per Square Centimeter. By P. W. Bridg.man . . . 319 



