March 21, 1919] 



SCIENCE 



287 



two sharp fringes make it possible to utilize 

 them even in eases when the auxiliary mirrors 

 vibrate. The vibration interferometer is quite 

 sensitive, provided the average currents are of 

 the order of several microamperes. 



On the Essence of Physical Relativity: Sir 

 Joseph Larmor, Cambridge, England. A gen- 

 eral discussion of the physics underlying rel- 

 ativity, with particular reference to an article 

 by Leigh Page. 



Gravitational Attraction in Connection with 

 the Rectangular Interferometer: Carl Barus, 

 Department of Physics, Brown University. 

 The rectangular interferometer is so sensitive 

 in the measurement of small angles that it 

 may be used for the measurement of the New- 

 tonian constant of gravitational attraction. 



The General Character of Specific Heats at 

 High Temperatures: Walter P. White, Geo- 

 physical Laboratory, Carnegie Institution of 

 Washington. The general law covering the 

 behavior of atomic heats from the lowest tem- 

 peratures up demands that at sufficiently high 

 temperatures all atomic heats at constant 

 volumes should have the value 5.96. A con- 

 trary hypothesis has been made, namely, that 

 atomic heats continue to increase witli the 

 temperature. The substances here examined 

 give evidence that the atomic heats do increase 

 above the value 5.96. 



On Certain Projective Generalizations of 

 Metric Theorems, and the Curves of Darhoux 

 and Segre: Gabriel M. Green, Department of 

 Mathematics, Harvard University. The con- 

 tinuation of earlier work by the same author 

 in the Proceedings. 



The Rectangular Interferometer with 

 Achromatic Displacement Fringes in Connec- 

 tion with the Horizontal Pendulum: Carl 

 Barus, Department of Physics, Brown Uni- 

 versity. 



The twelfth number of Volume 4 contains 

 the following articles: 



The Absorption Spectrum of the Novae: W. 

 S. Adams, Mount Wilson Observatory, Carne- 

 gie Institution of Washin^on. A discussion 

 of Nova Auriga; of 1892, Nova Persei of 1901, 

 Nova Geminorum of 1912, and Nova Aquilas 

 of 1918. The displacements of the lines in all 



these stars are directly proportional to wave- 

 lengths, and divide themselves into two pairs 

 of equal amount. Of these the first pair of 

 stars has exactly twice the displacement of the 

 second. In the case of Nova Aquite, there is 

 a progressive increase in the values of the dis- 

 placements of the absorption lines at successive 

 dates. Various hypothetical explanations are 

 discussed. 



On Jacohi's Extension of the Continental 

 Fraction Algorithm: D. N. Lehmer, Depart- 

 ment of Mathematics, University of California. 

 A closer study of Jacobi's expansion reveals a 

 number of remarkable points. Six theorems 

 are stated. 



A Characterization of Jordan Regions by 

 Properties having no reference to their 

 Boundaries :' Robert L. Moore, Department of 

 Mathematics, University of Pennsylvania. 

 The theorem is proved : In order that a simply 

 connected, limited, two-dimensional domain R 

 should have a simple closed curve as its bound- 

 ary it is necessary and sufficient that R should 

 be imiformly connected im kleinen. 



A Biometric Study of Human Basal Metab- 

 olism: J. Arthur Harris and Francis G. Bene- 

 dict, Nutrition Laboratory and Station for 

 Experimental Evolution, Carnegie Institution 

 of Washington. An analysis of measurements 

 on 136 men, 103 women, and 94 new-born 

 infants. 



Sex and Sex Intergrades in Cladocera: 

 Arthur M. Banta, Station for Experimental 

 Evolution, Carnegie Institution of Washing- 

 ton. The presentation of facts in regard to 

 Cladocera, with the discussion of their signifi- 

 cance with r^ard to sex intergrades in gen- 

 eral, leading to the tentative conclusion that 

 sex is always relative and that while most 

 individuals of whatever species are prevail- 

 ingly male or prevailingly female, every indi- 

 vidual may have something of the other sex 

 intermingled with its prevailing sexual char- 

 acters. 



On the Method of Progression in Polyclads: 

 W. J. Crozier, Bermuda Biological Station 

 for Research, Dyer Island, Bermuda. In tur- 

 bellarians generally, muscular operations anal- 

 ogous to those executed by the foot of chitons 



