EXPEDITION' TO 1'OINT I! A KRO\V, ALASKA. 



513 



THK VKIM'K 'Al. MA(i. \KTOMKTEU. 



Tlie length of 1 division of tin; scale is I"" 11 , the radius, mirror to scale, is 1.7 HI" 1 , hence; angular 

 value of 1 division of scale = 1'. In consequence of the great sensitiveness given to flic, instrument, 

 which was nearly double what it was intended it should have a few of the largest disturbances 

 were beyond the, range of the instrument during November, and thus tailed to be recorded. 



(1) Adjustment and determination of scale value September 9, 1882, noon. The knife-edge 

 was brought into the magnetic meridian on the leveled agate supports; the magnet was balanced 

 at ll h 22 m p. m., Gottingen time; the fixed and movable mirrors were made to read 500. 



Observations for time of otic oscillation 



and 



Ky Chronometer Bond 1 



(2) Readjustment November :>, lOi 1 ' p. in. (Gdttingen time), to November 4, 44 h a. m. (Gottiiigcn 

 time). Instrument releveled, fixed mirror made to read 500; also movable mirror adjusted to 

 division 50, 5 h 20'" p. in. (local time). 



*liy Chvonotiietcr liond 188. 



(3) TJalance magnetometer adjusted November 14, 1.SS2 (7 p. in. Gottingen time), so as to 

 oscillate in !l".OtiO and to read 500 at 10 h 05'" p. m. (Gdttingen time). This value for T was derived 

 from 20 oscillations; no particulars are recorded. No observations of oscillations with magnet 

 suspended. With 7', = 1X".0<H> and T= !IM>(>0 we have scale value in parts of the vertical force 

 0,0001 7:), which is eipial to 0.<!ii'2'_'.3 Knglish unit. 



(4) Keadjiistmeut of balance magnetometer March 4, 1883. Instrument leveled, with supporting 

 H. i; x . 41 i;,j 



