514 



EXI'KIHTIOX TO POINT BARROW, ALASKA. 



edge in magnetic prime vertical (7a. m. (lottiug-eu time): magnet balanced by means of weights, and 

 Vmtli mirrors brought to scale 50 (S a. in. (Jot tinmen time); magnet brought to oscillate in 11".850 

 by means of adjusting weight on upright stem (S a. in. (To'ttingen time). 



TO. . 



IM n.Hci Ilatii ms -, I*- jierfornicd* in 1 58.5 



in rl'orniMl in 1 58.5 



_'" <.jci Ihitinux urn- JMM iunnnl in 3 f>7.0 



Hi-mi- ir-ii'.x.-,(i With 7V - 18'.002aucl r=lK830 we bavo valneof oiitlivii<ni 



nl'si ;i]i-iM p:irt soft In- i) 11(11)1017, which cqnals 0.001300 Kncliih unit. 



* By Chronometer Bond 188. 



(.">) March 2!), 1883, about 4 a. m. (Gottingeu time) magnet removed, cleaned of slight frost 

 that had collected on it, and replaced between 4 and 5 p. m. 



(6) April 15, 1883, magnet raised from support and lowered between (i h '>.">'" and 7 1 ' 00'" p. in. 

 (Gottiugen time). 



(7) Readjustment of the balance magnetometer April 27. 18.S3. Instrument leveled. Sup- 

 porting edge in magnetic meridian for oscillations in horizontal plane 2' 1 I.! 1 " a. in. (Gottingen 

 time). Between 4 1 ' lo m and 5 h 40 m a. m. adjusted fixed and movable mirrors to scale division ">(>. 



Time of one oscillation = "'.816 Timp of one oscillation IXMOS 



Time of one oscillation = Gv074 



R: lionre 7"i = 18'.295 



TTcnce scale value for the time ju-eceding April 27, using T=7".816, one division =0.0(1(12 11.'! 

 part of the vertical force, or 0.00.'iii8(i Knglish unit, and alter A]>ril 27 using T=(>\974, one divis- 

 ion=t.00()3031 part of the farce, or 0.00.'W7(i Kuglish unit. 



(S) May '!. J883, magnet of balance magnetometer raised on support and lowered between 11 

 and 12 p. ni.((iottingeu time). Found time of one oscillation in t lie vertical pla ne =8". 750; hence with 

 T, = 18 8 .295, one division of the scale=0.000102(i part of the vertical force, or 0.002402 English 

 unit. 



(9) May 21. I.SS.'J. At 3 a. in. (Jottingeu time magnet fell oft' support ; replaced and time of one 

 oscillation determined 8'.700; hence one division of Ncale=0.0001948 part of the vertical force, or 

 0.002400 English unit. 



Increasing scale readings denote increasing vertical force. 



