and Levelling, §c. 343 



Polaris, 



1840, August 21. B = 29.70 in. t=Ci° 

 Error of Chron. at 10 J p. m. Fast 1™ 58 .4, Rate 19 s .7 gaining. 



Times. Yer. Z. D. Level. Z. D. 33° 31' log 1.5876 



+ — in, 



/,. ,,,. s . o / „ e o B = 29.70 log 9.9956 



1. 10 9 5 A 33 34 30 24 22 t = 64° log 9.9875 



B 34 25 * = 64 ° lo S 9 - 9 9° 4 



34 30 r= 37".2 log 1.5701 



2. 10 19 35 A 33 27 20 22 23 



Mean 10 14 20 B 27 20 46 45 



Error Cr. — 1 58.4 C 27 30 45 



M. T. I. 10 12 21.6 33 30 55.8 2|i 



Long. + 12 32.0 level + 0.5 q".5 



G. M. T. 10 24 53.6 33 30 56.3 



refr. + 37-2 



True Z. Dist. = 33 31 33.5 



h. m. s. 



Sidereal time at Greenwich, M. N. 9 59 29.28 



Mean time at place of observation, 10 12 21.60 



Reduction to Greenwich M. T. 10 h 24™ 54 s + 142.65 



Sidereal time of observation, 20 13 33.53 



Star's Eight Ascension, 12 36.78 



t = Sidereal time after transit, . . . . . 19 10 56.75 



By the preceding formula?, 



h. m. 8. 



t — 19 10 56.75 sec 0.51622 cosecant . . 0.02115 



p— 1° 32' 33".80 P.L. 0.28884 sec 0.000158 P. L. 0.28884 



u=— 28 11 .8 P.L. 0.80506 cos 9.99fi986 

 Z.D.33°31'33".5 cos 9.920976 



x=+56 30 9.2 ... sin 9.921120 cos 9.74186 



1= 56 157.4 N. «i'= N.2°39'44".6E. P. L. 0.05185 



2 



Table III. Surveying gives -A tana = cor = — 4 .6 



n = N. 2 39 40 .0 E. 



Hence the latitude /, deduced from this series, is 56° 1' 57".4 N., 

 and the azimuth of the star referred to the horizon, m = 

 N. 2" 39' 40".0 E. 



Now, the reading on the horizontal circle being recorded at 

 each observation, and referred to a lamp in a given position, 

 the azimuth of the lamp becomes known, as well as those of 

 any number of points whose angular bearings are compared 

 with it by observation. The latter, not being my present ob- 



