EXPERIMENTS WITH THE DISPLACEMENT INTERFEROMETER. 43 



risen to -i". The decline, however, at once commences, and on July 8 a is 

 about -3.3", from which it rises to -2.4" at the end of the work. The maxi- 

 mum range of the tilting of the pier, a, between April and July is thus about 

 from +2" to 4", or 6" of arc. 



24 



-/ 



-B 



^8 



16 



1-4 



it 



W 



8 



6 



4 



2 







-7 



7 



3579/7 



15 17 19 Z1 

 FlG. 24. 



25 S3 



3 579 



I2L 



A 





jr_ 



-/ 



_ .d 



& 



-5 

 -7 



-ee 



-gs 



- 



-2 



e la i?5 zt 



FIG. 25. 



6 8 



