Vhrtnixti'i/ ami Phyxu 



-a conditi. events the li£ 



-in -face coming to the eye, since it can only pi 

 slit ; the second surface of the flint to have t 

 3 contiguous surface of the crown, in order tt 

 oined with bnlxim. ihn- a\ ^'hling, as much 

 fit these surfaces; the remaining surface t<> 



ditions h 



avin- 





fulfilled by 



the 



m; 



akers, noi 





•i liu 



'■Te.'l 





uhe 

 i fh< 





1 the use < 





■ ..ti'i'!. 











t to the si 







ins. the liglr 









dently c 



<>me f 



mm :< 



. very small 



|M,V 



ti«. 



n of then 



hot!' and A 



ngst 



linn lay 



Princeton, : 



\Ly 



12, J 882. 



8. Relat, 







t>, ,*;<„, nf 





rcury.—l 





tin 





eury, and 



the 



changes 



Th^So^oniul 'u',' . th -n M-i ?■!'.'. «1 tr 



eijiial to that which would he -ccured l»y one having the usual 

 construction, with telescope and collimator mounted separately. 



With aRutherfurd grating of 17,000 lines to the inch, it 'can 

 easily -how manv <>f t he Kraunhotcr iine.-, which the maps of Kirch- 

 lown as single, to be composite. 



galvanic polarization and the surface 



pends upon polarization produced by electrical currents at the 

 surface of separation between mercury and dilute sulphuric acid. 

 Lippman has also maintained that the'magnitude <>\' the capillary 

 constant is modified by the difference of potential between 

 the two liquids at the surfaces «»t which the phenomena are stud- 

 ied. A controversy upon tin- point ha- ensued bet we, 

 and Quincke, and' Ilelmholtz suggested to Arthur Kbuig to 

 complete an investigation which had already been begun in the 

 Physical Laboratory, at Berlin. The experiments of Lippman 

 were repeated and were extended to various acids and solutions 

 of salts. In order to avoid the adhesion to glass surfaces, a form 

 of apparatus was employed by means of which the mercurv sur- 

 t if. was bounded by , minimum Mirt'ace of gla>s. The surface of 



served bv means of an optlialmometcr. The ingenious arrange- 

 ments by means of which the measurements of the change of 

 shape of the mercury surface were made are given at length. 

 Although the apparatus was placed upon a pier, the position of 



