LONGITUDE. 



203 



TABLE V— Continued. 



RECAPITULATION, 



Difference of results for longitude of station near Presidio del NortCy as obtained from computations 



of observed moon culminations ^ with tabular B, A, in Nautical Almanac and Greenwich observa- 

 tions y 1852. 



Longitude computed from tabular R. A. in Nautical Almanac 

 Longitude computed from Greenwich observations 



Difference between Nautical Almanac and Greenwich observations 

 Observed longitude of Cambridge east of establiahed longitude 



. 



Difference 



Longitude computed from tabular R. A. in Nautical Almanac, with correction^: applied 

 Longitude computed from Greenwich observations , 



Difference 



Longitude of station near Presidio del Norte 



A> m. t> 



6 57 19.95 



6 57 39.02 



19.07 

 11.26 



7.81 



6 57 31.21 



6 57 39.0-2 



7.81 



6 57 39.02 



TABLE YI. 



Tabulation of results for longitude of astronomical station near Fort Duncan^ derived from observa- 

 tions made with 30-mch transit (by Troughton & Simms) and sidereal chronometer No. 2440, 



%^ (by Parkinson & Frodsham:) By J, H. Clarh^ under the direction of Major W. II. Emory ^ 

 Chief Astronomer and Surveyor of United States and Mexican boundary survey. 



Date. 



1852. 

 Oct. 19 



20 



21 



21 



2a 



25> 

 23 

 23 

 25 

 25 

 26 

 26 

 27 



Authority for ele- 

 ments used. 



Moon's Ist Hmb. 



G. observations 



do 

 do, 



C. observations,. 

 G. observations,, 

 C. observations,. 

 G. observations , 

 C. observations.. 

 G. observations.. 

 U. observations, 

 G. observations.. 

 C. observations.. 



G. observations 



A. m. s. 



6 42 00.5 

 6 41 54.0 

 6 42 09.5 



04.3 

 6 41 58.2 



57.2 

 6 42 09.5 



05.7 



18.0 



13.3 



Resulting longitude 

 from observations 

 on moon's 1st limb. 



6 42 06.7 

 12.4 



6 41 57.25 



6 42 06.90 



6 41 57.70 



6 42 07.60 



6 42 15.65 

 6 41 49.1 



limb =6A, 42fn. 04s.l6. 



Date. 



1852. 

 Oct. 27 



28 



29 



30 



31 



Nov. 1 



2 



Authority for ele- 

 ments used. 



I 



Moon's 2d limb. 



G. observations 



do 



do 

 do 



do 



do 

 do. 



h» Tn. s. 



Resulting longitude 

 from observations 

 on moon's 2d limb. 



hi m. f. 



6 41 46.2 



6 42 01.3 

 6 41 53.3 

 6 42 04.4 

 6 42 02.6 

 6 42 04.9 

 6 41 46.5 



Mean longitude from moon's 2d limb = 6A. 41«i. 57s.03 



By giving double weight to the results of observations on moon's 1st Umb, we have longitude = 6A. 42m, 01s. 78 



Longitude of astronomical station near Fort Duncan = 6A. 42w# 0I«,78 



