600 



EXPEDITION TO POINT BAEBOW, ALASKA. 



Observations for determining the absolute magnetic declination Continued, 



[Date, Juno 30, 1883, local time. Instrument, niiitilar mafinelonn ter 

 No. 11. Magnet L,, suspended. Observers: Dark and llaxlield.] 



Time. 



Mean 



reading.*. 



Compntiiticiii. 



:ily 14, 1883, local time. Instrument, unitihir mapir 

 No. II. Magnet L y , susjM'Mliil. < His.'i % ,-i ,~. I>ai k ami Maxlielil. | 



Time. 



Mean 

 scale- 



readings. 



Computation. 



8a.m. 

 8 a. in . 



10 ft. in . 



11 a. ni . 



12 in... 

 1 p. in. 



d. 



39.0 

 48.0 

 43.0 

 45.0 

 53.0 

 50.0 



Keating of mark. 



At beginning of a. m. ob- < A . 359 56 



serrations (11. 58 



At end of p. m. observa- < A. 



tions (B. 58 



Mean . 



359 57 



8a.m 



11 a. in 



loa. m 



11 a. m 



12m 



1 p. m 



^ ReadiiKj of mark. 



us of a. m. ob-< A. 359 



) I!. 



::.() At end "I p. m. niiBi-rva v A. X,'J 



I'.l.'.l tiona ) IJ. 



27. ii 



18.1 Mean 



Brooke declinometer 

 readings. 



8a.m ............ 448 



Valneof one division of scale =3'. 69 



9a.m 

 10a,m 

 11 a,m 

 12m 



Ip.in 



498 

 48i 

 484 

 514 

 499 



i, -ading of axis 



Mean Bcale*reiwliiiK of B. and 

 W. magnetic elongation... 43. 13 



Brooke declinometer 



filiation ofa.\is of m 



Scale. 



diff.= 



8.34 



Reduction to axis . 



Azimuth circle Teada 347 48.5 



Magnetic meridian read* 348 19.3 



d. 



40.33 487.5 

 475.7 



-3.20 = U.8 



Mean reading of murk 359 57.0 



Azimuth of mark K of N ... 46 36.0 

 True nieiidian reads 313 21.0 



Magnetic declination 34 58. 3 



Line of dotorsion. 60 

 A,, circle... {A- 347 48 

 Lino of dptorsion 62 



N. B. Instruments very much disturbed all the morning. 



* From observations ot'AIay 31 anil July 14, 1883. 



Ka.m ............ 513 



It :i. m ............ 474 



10 a. m ...... ...... 482 



11 a. m ............ 404 



12m .............. 471 



Ip.m ............ 41,7 



ings. 





29.00 



478.5 

 473. !t 



1. 6 



0.-.. A 

 4ti. 4 

 111.',! 

 36.0 

 02.6 



:i2. 7 

 30.0 



18.10 

 51.30 



17.80 



17.80 



1C. 30 



17.95 

 B1.75 



B2. -jr. 

 16.80 



t. 



34.55 



- 1.25 = 4.6 

 27.75 



Lineofdetorslon. 324 



A ,.i 5 A- 349 33 

 Az. circle ^ B 35 



Lineof detovsion. 275 

 Till 1 p. ill., tlien. 9;JO 



reading of axis 34.72 



Mean scale-loaning i if K. and 



W. in on... 27. 7,"i 



diff.= 6.117 



Redaction to ails ........... u 



A/.iimitli circle leaiifl ....... 34!t 



2.V 7 

 34.0 



Magnetic meridian reads. 3!i< 



Mean 1 1 vk 359 



Azimuth of mark K. of X ... 4U 



True meridian reads 313 



Maglietic <it rlination 



56.5 



47.8E. 



N. B. Xew Knspension thread put in just before observation. 



[Date, July 31, li*S;i, local time. Instrument, nnifllar magnetometer. 

 Magnet I., suspended. (Jliserver: A. C. Dark.l 



Time. 



8am. 



I) a. in . 



M a . 1 1 1 . 

 l.'m .. 

 1 p. in. 



Mean 

 scale- 



readin:s. 



d. 



39.0 



X',. (I 



J!l. 



29.0 



46.0 



45.0 



readings. 



t* a. m . 477 



'.la. in 455 



111 :i. m 449 



1! a. in 449 



511 



1 ]>. m 515 





3C. 26 



170. 

 47D.il 



2. 1 



Llneoffotoreloii -''it) 



. . , ) A. 358 09 



"IB. 11 



I.ilienf lli lorsiou 108 



Computation. 



Reading of mark. 



At beginning of a. m. ob-( A. 359 56 



S( i rations ............. ) B. 57 



At end of p. m. observa- ( A. 359 56 



tions ................... ) B. 57 



Mean 



359 56.5 



Value of onedivision of scale. =',','. 69 



Scale-reading of axis ....... 



Me;in M'ale-ivrulin;; ol' 1C. and 



35. OS* 

 . 

 W. magnetic elongation... 36.26 



ill If. 1.17 



Reduction to axis +0 4.3 



Azimuth circle reads 353 10.0 



Magnetic meridian reads. 353 14.3 



Mean reading of mark 359 56.5 



Azimuth of mark E. of N ... 46 36.0 



True mi i iili.. n reads 313 2(1. B 



Magnetic declination 39 53. 8E. 



N. U. liolli insti niuents niueli disturbed. 



'inns of July 14 and August 14. 



(Date. August 14, 1J-83, local time. Instrument, unililai 



u-i-Xo. 11. Magnet L,, impended. Oi,sev\eis ; DarkandMaxlield.] 



Time. 



8a.ni. 

 9 a. m . 



Ill a. m . 



1 1 a. m . 



12m ... 



1 p. m. 



Mean 

 Boale- 



readings 



d. 



39.0 

 40.0 

 37.2 



L'll. 4 

 IS. 7 

 40.2 



Brooke dprlinometer 



readings. 



8a. m 41W 



9a. m 40H 



10 a. m 481 



11 a. m 457 



12m 419 



1 p. m 021 



Mean. 



d. 

 35.08 



477.8 

 473.3 



-1.22 =4.5 



33.86 



Lineofdetorsion. 30 



A*. ,. ire i,.. .{ 



Lineofdetorsion. 27 



uation. 



mark. 



i.t a. m. ob-J A. 359 57 



se vvat ions ) I!. 



At end of p. m. olwerva- V A 

 tions i 1.. 58 



Mean 359 .',7.5 



Determination of axis of it 



85. 



81.7 

 31.8 

 32.0 



37.2 

 40.8 

 37.3 

 411. S 

 34.9 

 42. 8 



Altn'te 

 mean. 



33.90 



37. !IO 



37.30 

 33.50 



33. 78 

 33. 47 

 33.40 



Axis. 



d. 



35.'29 

 3S.B9 



Valueofonedivision of scale. =3' 







Me'Ml sralr re, dill;: of 1-'.. and 



\V. m. .:ition... 



30. 4C 

 33.80 

 diff.= 1. 00 



Jleduetion tonxia ........... 



Azimuth circle leads ....... 348 



5.9 



57. "i 



Magnetic meridian reads. 34^ 51.6 



Mean reading of mark ...... 359 57.5 



A/imnt li of mark E. of X ---- 4G 36 



True merid inn reads ........ 313 21.5 



Magnetic declination 35 30. 1 E. 



