ASTRONOMY. 



n 



o 



from observations on 8 Ursce 3Iinoris^ eastern elongalioUj/or the value of 



f 



3Iarch23, 1855. 



No. 



1 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 



15 



16 



17 



18 



Micrometer 

 readings. 



400 

 3o0 

 300 

 250 

 200 

 150 

 100 



50 

 



50 



100 

 300 



350 



450 

 550 

 750 

 850 

 900 



Time of ob- 

 servat'n by 

 chron'r. 



Time from 

 elongation. 



h. m. s. 



11 46 25.0 



46 59.5 



47 36.5 

 4S 13.5 



48 50.0 



49 23.0 



49 58.8 



50 35.0 



51 08.5 



51 43.0 



52 19.0 



54 46.0 



55 19.0 



56 33.0 



57 45.0 



12 00 04.5 

 01 17.0 

 01 51.6 



3.9 

 3.4 



2.8 



2.1 

 1.5 

 1.0 

 0.4 

 0.2 

 0.7 

 1.3 

 1.9 

 4.3 

 4.9 

 6.0 

 7.3 

 9.6 

 10.9 

 11.4 



Correct-n for Reduced time 



n. 



0.0 

 0.0 



0.0 

 0.0 

 0.0 

 0.0 

 0.0 

 0.0 

 0.0 

 0.0 

 0.0 

 0.0 

 0.0 

 0.0 



0.0 

 0.1 

 0.9 

 0.9 



No 



A. m. <. 



11 46 25,0 



46 59.9 



47 36,5 



48 13.5 



48 50.0 



49 23.0 



49 58.8 



50 35.0 



51 08.5 

 51 43.0 

 59 19.0 



54 46.0 



55 19.0 



56 32.0 



57 45.0 



12 00 04.4 

 01 16.8 



01 51.4 



19 

 20 

 21 

 22 

 23 

 24 

 25 



26 

 27 

 28 

 29 

 30 

 31 

 32 

 32 

 34 

 35 



Micrometer Time of obscr-, Time firom 



readings. 



1000 



1050 



1100 



1150 



1250 



1300 



1350 



1400 



1500 



1550 



1600 



1700 



1800 



1850 



1300 

 1950 

 2000 



I 

 vat'nbychro- cloajation 



nomctcr. 



A. fll. 1. 



la 03 06.0 



03 40.5 



04 15.8 

 04 52.5 



*06 04.0 



06 40.8 



07 16.0 



07 51.6 



08 58.0 



09 33.0 



10 08.0 



11 21.8 



12 31.5 



13 07.0 



13 44.5 



14 19.6 

 14 57.0 



Coriect*nfor Reduced tima. 



a. 



m. 

 12.7 



13.1 

 13.9 

 14.4 

 15.6 

 16.3 

 16.8 

 17.4 

 18.5 

 19.1 

 19.7 

 20.9 

 22.1 

 22.7 

 23.3 

 23.9 



94.5 



L 



m^ $, 



12 03 05.4 





03 40.1 





04 15.3 



<M 51.9 

 OG 03.3 



06 40.0 



07 15.1 

 07 50.6 

 OB 56.8 



31.7 



10 0G.6 

 U 90.0 

 19 29.5 

 13 04.7 



13 43. d 



14 17.0 

 14 54.0 



Remarks. 



Timeby chronometer of eastern elongation of ^ Ursac Minnri3 lU. SOn*. 24*.i60 



'Chronometer slow • ^ 98m. 41f .49 



Declination of star = 86° 35^ 32^^5. 



)/ results for tie determination of one division of the micrometer, derived f 



o^nh'nnsi nn n llrscB Minoris near eastern elongation. 



Nob. 



I to 18 



S to 19 



3 to 20 



4 to 21 



5 to 



6 to 23 



7 to 24 



8 to 25 



9 to 26 



10 to 27 



11 to 28 



12 10 29 



13 to 30 



14 to 31 



15 to 32 



16 to 33 



17 to 34 



18 to .35 



Micro m'er 

 divisions. 



Differences 

 of times. 



1300 

 1350 

 1350 

 13j0 

 1350 

 1400 

 1400 

 1400 

 1400 

 1450 

 1450 

 1300 



1350 

 1350 

 1300 

 1100 

 1100 

 1100 



Differences of Reduction to Values of 

 times in arc. I the equator, one division. 



I 



15 19,7 

 13 00.3 

 13 00.2 

 13 02.8 



/ // 



15 26.4 



16 05.9 

 16 03.6 

 16 01.8 

 16 01.9 

 16 40.3 

 16 41.2 

 16 40.1 



16 42.1 



17 13.8 

 17 12.7 



15 20.6 



16 01.0 

 15 57.5 i 3 59 22.5 



3 51 36.0 



4 01 28.5 

 4 00 54.0 

 4 00 27.0 

 4 00 28.5 

 4 10 04.5 

 4 10 18.0 

 4 10 01.5 



4 10 31.5 

 4 18 27.0 



4 18 10.5 



3 50 09.0 



4 00 15.0 



3 49 55.5 

 3 15 04.5 

 3 15 03.6 

 3 15 42.0 



/ // 



13 45.3 



14 20 5 

 14 18.4 

 14 17.8 



14 16.9 

 14 51.0 

 14 51.9 

 14 50.9 



14 52.7 



15 20.8 

 15 19.8 



13 40.1 



14 16.1 

 14 13.0 

 13 39.3 

 11 36.3 

 11 35.2 

 11 37.5 



// 



.63484 

 .63888 

 .63585 

 .63547 

 .63474 

 .63642 

 .63771 

 .63535 



.63764 

 .63503 

 ,63433 

 ,63077 

 ,63474 

 .63185 

 ,63023 



.63300 



.63200 



.63409 



II 



Mean= 0.63466 





Noa. iMicrom'er 



divisions. 



Differences [ Differences of Reduction to Values of 

 of times. times in arc. ., the equator, one div'n. 



1 to 35 



2 to 34 



3 to 33 



4 to 32 



5 to 31 



2400 

 2300 

 2200 



6 



to 30 



7 



to 29 



8 



to 28 



9 



to 27 



10 to 26 



11 to 25 



12 to 24 



13 to 23 



2100 

 2000 

 1850 

 1700 

 1600 

 1500 

 1350 

 1250 



1 



nil 



900 



28 29.2 

 27 17,5 

 26 08.0 

 24 53.5 

 23 39.5 

 21 57.0 

 20 07.8 

 18 56.7 

 17 48.3 

 16 03.6 

 14 57.0 

 11 54.8 

 10 45.0 





1st series— mean 

 2d series— mean 



Kesult by i Ursa Minoris 

 Result by Polaris 



Final result 



/ // 



7 07 18.0 

 6 49 22.5 

 6 32 00.0 

 6 13 22.5 

 5 54 52.5 

 5 29 15.0 

 5 01 57.0 

 4 44 10.5 

 4 27 04.5 

 4 02 09.0 

 3 44 15.0 

 2 58 42.0 

 2 41 15.0 



25 20.0 

 24 16.5 

 23 15.0 

 ^ 09.0 

 21 03.3 

 19 32.4 

 17 55.4 

 16 52.3 

 15 51.5 

 14 22.8 

 13 19.2 

 10 37.0 

 8 35.9 





.63333 

 .63317 

 .63409 

 .63285 



.63165 

 .63373 

 .63288 

 .63260 

 .63433 

 11 



iX4 



.63935 

 *63700 

 .63068 



0.63492 

 0.63466 



0.63479 



0.64319 



0.6389V 



Valutt of one 



divi^oa of t.e ..cro^eter .o. Csen-ation. on Polari. (weste. elongation) and S Vr^ Mino^ (casun. e.on^Uon) U ...6««. 



Obicrver, Lieut 



. N. Michler, U. S. Topographical Englueer.. Computer, Hugh CampbeU. 



