72 



U. S. COAST AND GEODETIC SURVEY 



(fig. 27) from a comparison with simultaneous observations at a 

 standard station suitably situated. The form provides for the com- 

 putation of the local intervals and contains an explanation of its use 



OCPAMTMBNT OP COMMKRCB 



M.y. tins TIDES : Comparison of Simultaneous Observations 



;A)SuWdinate8Ution....A?».90rtes, Wash. _ Lat. . .M".. 31 !...N. tong. 122° 36' ;7. 



(B) Standard station .?eat 1 1 6 ,.. Wai _ Lat. _470 .37'. N. Lo^ i.???. ..20»...i(".' 



Chief ol party Time Meridian: (A) ...1.8Q.?...ff (B) 



(1)= 



(2) = 

 (3)- 



(4)= 

 (6)= 

 (8) = 

 (10)= 

 (12)= 



(14)= 

 (16)= 

 (18)= 

 (20)= 

 (22)= 



BW. 



-0.09 



..rO.,.C2.. 

 -0.11 



.~!y.»My... =MeaD difference in time of high and low water respectively. 

 ..-.Qt.v.iv .. =CorTection for difference in longitude. (Table on back of form.) 



=(l)+(2)=Mean difference in high and iow water inter\*als, respectively. 



..22...S4. 

 ..22,.Q0. 

 ....0...94. 

 22.47 

 ....4...67. 



...A.ZA. 

 ...A,2Z. 

 ..r0..19. 

 ....4.-.64 

 ..-2.,.82. 



=Mean IIHW height at (A). 



=Mean LHW height at (A). 



=(4)-(6)=2DHQat(A). 



= }[(4)+(6)l=Mean HW height at (A). 



=(10)-(ll)=Mnat(A). 



=Mean HHW diCfeience. 



=Mean LHW difference. 



= (14)-(16)=2DHQ difference. 



=J((14)+(16)]=Mcan HW difference. 



=(20)-(21)=Mn difference. 



(24)=_Oi622_=(12)-t-I(12)-(22)l=Mn laUo. 



(5) =...2.Q...0.4...=Mcan HLW height at (A). 



(7) =..lEr.&7..=Mcan LLW height at (A). 



(9) -»....4...4.7..=(5)-(7)=2DLQat (A). 



(n) = ..1.7....e0.. = 5[(5)+(7)]=Mcan LW height kt (A). 



(13)=..2Q.?.14..= j((io)+(n)]=MTL at (A). 



(15)=....7.'.2.9...=Mcan HLW difference. 

 (17)=....7.'..71..=Mean LLW difference. 

 (19)=. .-Q....5L.. = fl5)-(17)=2DLQ difference'. 

 (21)=....7.-..4.6..=j((i5)+(i7)]=Mean LW diflerenca. 

 (23)= &i££_=)[(20)+(21)]=MTL difference. 



(25)= 0.832 =(8)-!-[(8)-(18)]=DHQ ratio. 

 (26)=JLC2fi_=(9)^[(9)-(19))=DLQ ratio. 



Mean LWon etaS at subordinate etation=MTL — JMn = feet. 



Mean LLW on suff at subordinate station=MTL-lMn-DLQ=..J.5^19....feet. 



Computed by . 



C. D. A. 



.l..-...1.2...-..2.?._ Verified by I.i.h.'^.:. 



(D««.) 



.5.-.12...-_27 

 ("Diii.) 



Figure 27. — Form 248, comparison of simultaneous observations. 



on the back. The table on page 73 may be used to obtain the correc- 

 tion for difference in longitude. The Greenwich lunitidal intervals 

 at the subordinate station may be obtained by the simple application 

 of the mean differences in the time of high and low water to the 

 corresjjonding Greenwich intervals at the standard station. 



