RECORD AND RESULTS OF 



Observations for latitude, August Tth. Reflecting circle. 

 Circummeridian altitudes of the sun. 



Index J+g' ^J" —f^' qJ"I, correction +1' 0t".5 



Pocket chronometer. 



2 Q Pocket chronometer. 







20 



IQh [,om 0^8 



68° 15' 1^2" IP 02- 55' 







6T" 



"'{IT 



10 51 32 



68 11 I^J 11 04 20 







6"? 



"{S 





2© 







20 



10 54 02 



G1 14 1^2 11 05 52 







68 



19 -[30 

 ^■^ 130 



10 55 10 



67 15 I^J 11 01 08 







68 



19 -|20 

 ^■^ 130 



T = +54°, B=2 



9-80 at 60° Index {+g' ^J" -30' 



40"} 

 40 ]■ ' 



correction -f 50 





Intermediate set of observations with W.'s sextant. 







T ^ C+3r 05" —32' 00") ^ 



Index 1^3^ 20 -32 15 } Correction- 



-27".5 







Pocket chronometer. 



20 





lO'' 50'° 



51' 



67° 16' 



20 



51 



56 



17 



10 



58 



4T 



17 

 20 







10 59 



47 



68 19 



30 



11 00 



52 



19 



20 



11 01 



41 



20 



15 



let chronometer. 



20 





ll"" OO-" 



31» 



68° 19' 



10 



10 



36 



18 



20 



11 



20 



18 

 20 



20 



11 12 



32 



67 14 



50 



13 



42 



14 



15 



14 



27 



14 



10 



We have, according to Gauss' metliod of reduction (Chauvenet's Spherical and 

 Practical Astronomy, Vol. I, p. 244), with the assumed longitude 3^.703 west of 

 Greenwich : — 



8 = sun's declination at apparent noon . . . = +16° 16' 05". 4 

 5i= " " mean " ... =+16 16 09.2 



A§ ^ hourly increase of declination, + for sun moving northward = — 42". 3 

 ^1= meridian zenith distance = ^ — 3^56° 06' 55" 

 3 = hour angle of maximum altitude (in seconds of the chronometer) = 



[9.40594] — - ; the angular brackets include a logarithm. 



A = h^ ■ — J~ — for the sun and a mean time chronometer. 



sm ^i 



Jc^ = a tabular number having for its argument S T — hE, that is, the daily rate 



of the chronometer less the daily increase in the equation of time E, 



which is positive when additive to apparent time. 



S^==— 7^4, hT= +1^5, A;i = [0.00009], ^ = +0.35004 andS.=— 30\8. 



^ = ^ — Am 4- ^1 4- ?/ where m is a tabular number depending on the hour angle 



^^ reckoned from the instant the sun reaches its maximum altitude, — Am 



2 sin ^- 3' 

 the reduction to the observed zenith distance and y =^ A — ^ — ^^ — 0.'2 



sin 1" 



