^- -r*- --^J - 



26 



TIDES. 



[Sect. IV 



Thus, if high water occur at 5 o'clock when the tinie of moon's transit 

 is 3h., the luxiitidal inter val is 2h. ; and the correction (if the first table 

 be applicable) is — 47 m. ; hence the establishment is 2 h. 47 m. 



\ 



Sect, 



\ 



NOTE B. 



Note to Akticle 25. 



The Rule rf the DiAtrnal Inequality. 

 The Diurnal Inequality depends upon the moon's declination, as has 

 been said already. It increases from up to its maximum, and de- 

 creases to again, as the declin. on does so; following these changes at 

 an interval of one, two, or three- days, accordinc? to the aee of the tide. 

 The rule is expressed in this way : 

 For north declination of moon, 



Add to the tide following moon's south transit ; 

 Subtract from the tide following moon's north transit. 

 For south declination of moon, 



Subtract from the tide following moon's south transit; 



Add to tlie tide following moon's north transit. 

 The south transit is the miperior transit in the northern hemisphere, 

 and the north transit the inferior. The ccmtrary is the case iu the 

 southern 



Form for Tide Obs£rvatioks, 



Tides observed at 



, Lat, 



Long, 



By 



Mode of observation 



ivlode of deducing H. W. and L. W. 



/Fixed scale in open water ? 



{ Tube with float ? 



I Self-registering gauge ? 



r Mere looking ? 



lOrdinates every 5 m. near max. ? 



1348. 



Hi^h Water. 



1 I 



Low Water. ! Wind. 



Month. I Day. iHr^^ht. j Time. 



Height. ! 



I 



I" 



1 A.M. 



2 A.M. 



3 A.M. 



,-,, ; Barom. jTransit. 



Time. ' 



I 





V 



I 

 Moon*s*|LuTiitidal ' 



Interval, 



H. VV. 



\ 







• These colum:;:? to be filled at leisure (see Art. 13, 41). 



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