182 ASTRONOMY FOR 1><89, 1800. 



Variable stars. 



CilANDLKiJ (S. C.) The period of U Corouas. AHtroii. Jour., '.) : !)7-;>. 



. The variable. Y Cygui. Astroii. Jour., 9: '.12-;!. 



. Liglit-variatious of U Cephei. Astrou. Jour., 9: -r.)-.'):?. 



. General relations of variable star i)lienoinena. Astron. Jonr,, 9: 1-5. 



. Contributions to the knowledge of the inequalities in tiie periods of the 



variable stars. Astron. Jour., 8: lOl-O, 172-5. 

 [Pickering (E. C.)] Index to observations of variable stars. Ann. Harv. 



Coll. Obsiy., 18: 215-57. (v. 18, no. 8.) JJ.w, Reprint. 

 ScnONFELD (E.) Ephemerideu veriinderlicher Sterne fiir 1890. Vrtljschr. d. 



astron. Gesellseh., 24: 220-34. 

 Ykxdkli. (P. S.) Corrigendum to the elements of X Cygni. Astron. Jour., 9: 8. 



Venus. 



SciiAPAi{ELi-i. Transl.byTesbyLee. L'Astron.,9: 285, 325, 411. Aug. and Sept. 

 Yale Observatory. 



Thansactions'. . . v. 1, pt. 2. Researches with the helionieter. Determination 



of the orbit of Titan and the mass of Saturn, by A. Hail, jr. [:{7] p. 4to. 



New Haven, 1889. 



