PHYSICS. 377 



shape for publication some 500 folios of the courtesy phrases of 

 Samoan life (the fa' alupega). In this work I have completed the work 

 for the lesser archipelago of Manu'a and have covered rather more 

 than half of that for our other American possession, the island of 

 Tutuila. At the present rate of progress it is hoped to have this 

 specific study completed for the whole of Samoa in the next j'ear. 

 In such work as this it is apparent that two stages are requisite. In 

 the former the unpublished material which has been gathered pain- 

 fully from not always willing Samoan sages must be edited, translated, 

 and annotated and printed in order to be set within the reach of 

 students. In the latter stage this material must be assembled in 

 a lexicon, with the fullest possible gathering of material derivable from 

 other branches of the language family. 



Acknowledgment is to be made of the generous hospitality extended 

 by the University of Pennsylvania, the American Philosophical 

 Society, and the Academy of Natural Sciences of Philadelphia; their 

 library facilities have been placed unreservedly at my disposal, and 

 thus I have been enabled to collate a greater number of the series of 

 transactions of the great learned societies of the world than would be 

 feasible elsewhere in this country ; it could be equaled only in the greater 

 centers of scientific life in Europe, and that recourse is for the present 

 closed to the student. 



PHYSICS. 



Bams, Carl, Brown University, Providence, Rhode Island. Continuation of 

 investigations in interferometnj . (For previous reports see Year Books 

 Nos. 4, 5, 7-14.) 



Professor Barus has just submitted to the Institution a complete 

 account of his recent experiments in interferometry.^ One part of 

 these researches contains the results of such applications of the dis- 

 placement interferometer to which advance reference was made in 

 the preceding annual report. The other part treats of the phenomena 

 of superposed identical spectra. The account has been given chron- 

 ologically, although many of the anomalous features, in which the 

 interferences first presented themselves, were largely removed in the 

 later work; for the methods used in the several papers, early and later, 

 are throughout different. It therefore seemed justifiable to record 

 them, together with the inferences they at first suggested. The 

 pursuit of the subject as a whole was made both easier and more 

 difficult by the unavoidable tremors of the laboratory, inasmuch as 

 it is possibly easier to detect an elusive phenomenon if it is in motion 

 among other similar stationary phenomena; but it is certainly difficult, 

 thereafter, to describe it. 



1 Carnegie Inst. Wash. Pub. No. 249. 



