40 



Land Magnetic Observations, 1905-10 



Magnetic Observations and Computations. 

 Declination Observations with Compass. 



Station: Middlebury, Vt. 



Date: Thurs. July 28, 1910 



Instrument: Compass Dip Circle No. 178 



Mark: East gable of C. James house 

 Observer: P. N. S. 



Chron. No. 256 



Chron. 

 time 



h m 

 14 05 



14 30 



14 17.5 



Means 



II 



m 

 17 24 



17 35 



17 29.5 



Means 



Mark 

 beginning 

 R. and D. 



302 05.5 



122 05.5 



302 05.5 



302 05.5 



302 06.0 



122 05.0 



302 05.5 



302 05.5 



Instrument direct 





Needle 



at 

 at0 



North end 



178 07 

 07 



178 08 

 08 



178 07.5 



South end 



178 05 

 05 



178 06 

 06 



05.5 



178 06.5 



178 11 

 12 



178 10 

 10 



178 12 

 12 



178 11.8 



178 10 

 10 



10.0 



178 10.9 



Needle 



at 5 E. 

 at 5 W. 



South end North end 



173 05 

 02 



183 07 

 05 



04.8 



173 07 

 08 



183 07 

 09 



07.8 



178 06.3 



173 10 

 09 



183 11 

 11 



10.2 



173 11 

 10 



183 13 

 12 



11.5 



Mark 



ending 



D. and R. 



o / 



122 05.5 



302 05.5 



302 05.5 



122 05.0 



J02^ 06.0 

 302 05.5 



178 10.8 



Chronometer correction to L. M. T.: +7"" 



Local mean time 



Mag'c S. M. reading 



Mark reading . 

 Azimuth of mark* 

 True S. M. reading 



Magnetic declination 

 Index correction 

 Diurnal var. correction 

 Resulting declination 



Mean 



Remarks 



* Counted from south around by west. 



