Nov. 27, 1884] NATURE 



»3 



In the negative — 



San Domingo. 

 Abstaining from voting — 



Brazil, France. 



Ayes, 22 ; noes, 1 ; abstaining, 2. 



III. " Resolved, That from this meridian longitude shall 

 be counted in two directions up to 180 degrees, east 

 longitude being plus and west longitude minus." 



This resolution was adopted by the following vote : — 



In the affirmative — 



Chili, Liberia. 



Colombia, Mexico, 



Costa Rica, Paraguay, 



Great Britain, Russia, 



Guatemala, Salvador, 



Hawaii, United States, 



Japan, Venezuela. 



In the negative — 



Italy, Sweden. 



Netherlands, Switzerland. 



Spain, 



Abstaining from voting 



Austria-Hungary, Germany, 



Brazil, San Domingo, 



France, Turkey. 



Ayes, 14 ; noes, 5 ; abstaining, 6. 



I V. " Resolved, That the Conference proposes the 

 adoption of a universal day for all purposes for which it 

 may be found convenient, and which shall not interfere 

 with the use of local or other standard time where 

 desirable." 



This resolution was adopted by the following vote : — 



In the affirmative — 



Austria-Hungary, Mexico, 



Brazil; Netherlands, 



Chili, Paraguay, 



Colombia, Russia, 



Costa Rica, Salvador, 



France, Spain, 



Great Britain, Sweden, 



Guatemala, Switzerland, 



Hawaii, Turkey, 



Italy, United States, 



Japan, Venezuela. 

 Liberia, 



Abstaining from voting — 



Germany, San Domingo. 



Ayes, 23 ; abstaining, 2. 



V. " Resolved, That this universal day is to be a mean 

 solar day ; is to begin for all the world at the mo.nent of 

 mean midnight of the initial meridian, coinciding with 

 the beginning of the civil day and date of that meridian, 

 and is to be counted from zero up to twenty-four hours."' 



This resolution was adopted by the following vote : — 



In the affirmative — 



Brazil, Liberia, 



Chili, Mexico, 



Colombia, Paraguay, 



Costa Rica, Russia, 



Great Britain, Turkey, 



Guatemala, United States, 



Hawaii, Venezuela. 

 Japan, 



In the negative — 



Austria-Hungary, Spain. 



Abstaining from voting — 



France, San Domingo, 



Germany, Sweden, 



Italy, Switzerland. 



Netherlands, 



Ayes, 15 ; noes, 2 ; abstaining, 7. 



VI. " Resolved, That the Conference expresses the 

 hope that as soon as may be practicable the astronomical 

 and nautical days will be arranged everywhere to begin 

 at mean midnight." 



This resolution was carried without division. 



VII. " Resolved, That the Conference expresses the 

 hope that the technical studies designed to regulate and 

 extend the application of the decimal system to the 

 division of angular space and of time shall be resumed, 

 so as to permit the extension of this application to all 

 cases in which it presents real advantages." 



The motion was adopted by the following vote : — 



In the affirmative — 



Austria-Hungary, Mexico, 



Brazil, Netherlands, 



Chili, Paraguay, 



Colombia, Russia, 



Costa Rica, San Domingo, 



France, Spain, 



Great Britain, Switzerland, 



Hawaii, Turkey, 



Italy, United States, 



Japan, Venezuela. 



Liberia, 



Abstaining from voting — 



Germany, Sweden. 



Guatemala, 



Ayes, 21 ; abstaining, 3. 



Done at Washington, October 22, 1884. 

 C. R. P. Rodgers, Rear-Admiral U.S.N. , President, 

 L. Cruls (Brazil), Janssen (France),"! r fr „ tnri .. 

 R. Strachey (Great Britain) . . . ]* ecrelartes - 



" Resolved, That a copy of the resolutions passed by 

 this Conference shall be communicated to the Govern- 

 ment of the United States of America, at whose instance 

 and within whose territory the Conference has been 

 convened." 



OX THE INTERFERENCE-CURVES KNOWN 

 AS "OHM'S FRINGES" 



PERHAPS I may be allowed to recall the attention of 

 physicists to the above "strange and interesting 

 phenomena," as they are rightly called by their dis- 

 coverer, Prof. G. S. Ohm (see Pogg. Annalen for 1853, 

 vol. xc. p. 327) ; partly for the purpose of indicating a 

 simple method of observing them. 



According to Prof. Ohm's directions two plates of equal 

 thickness are to be cut from a uniaxial crystal, with 

 parallel surfaces making an angle of 45° with the optic 

 axis. One of these plates is to be placed on the other in 

 such a position that the optic axes lie in the same plane 

 but on opposite sides of the normal common to the two 

 plates, with which they make, of course, equal angles of 

 45°. When this combination is held in a convergent 

 beam of plane-polarised monochromatic light (e.s;. yellow 

 sodium light), numerous alternations of bright and dark 

 elliptical bands are seen, most distinctly when the plane 

 containing the optic axes makes an angle of 45° with the 

 plane of polarisation of the light. 



Of course a pair of " Savart's band " plates, when pro- 

 perly oriented, will answer for the above experiment ; but 

 the peculiar double refraction of quartz causes more 

 complicated but beautiful results. 



