A Magnetic Survey of the Fortieth Parallel. 

 Table IIIb.— Magnetic Intensity. 



143 



New Haven . . 



La Junta 



Man it on 



Denver 



Cheyenne 

 Salt Lake City 



Ogden 



GTreen River . . 

 Grrand Island . 

 Council Bluffs 



Chicago 



Allegheny .... 

 Washington . . 



British Units. 



Hori- 

 zontal 

 Force. 



•8610 

 •2761 

 •0649 

 •9847 

 •7348 

 •0061 

 •9440 

 •8069 

 •5675 

 •3663 

 •0671 

 •1294 

 •3608 



Vertical 

 Force. 



7001 

 8717 

 9245 

 0619 

 3561 

 8156 

 8821 

 1048 

 7531 

 7493 

 0232 

 8040 

 5096 



Total 

 Force. 



2740 

 9913 

 9555 

 0513 

 2322 

 8324 



0243 

 5463 

 4763 

 6435 

 4534 

 2479 



Metric Units. 



Hori- 

 zontal 

 Force. 



•7802 

 •4327 

 •3353 

 '2983 

 1831 

 '3082 

 2796 

 '2164 

 1060 

 0132 

 8753 

 9040 



2 -0107 



Vertical 

 Force. 



•8558 

 •4738 

 •4981 

 •5615 

 •6972 

 •4479 

 •4786 

 •5813 

 •8802 

 •8784 

 •0047 

 •9037 

 •7679 



Total 

 Force. 



•1204 

 9900 

 •9735 

 •0177 

 •1011 

 •9168 

 •9339 

 •0052 

 •2459 

 •2137 

 ■2907 

 •2031 

 •1083 



The following observations of horizontal force in absolute measure 

 were made at Kew with the Owens College unifilar before and after 

 the American observations. 



G-. M. T. 



h. m. 



4 24 



5 02 



June 7, 1878. — Deflection Observations. 



Distance of centre rr Observed 

 Temp. n 

 of magnets. deflection. 



ft- o o / // 



1-0 . . 77 -4 . . 16 29 18 . 

 1-3 . . 77 '4 . . 7 25 46 . 



Vibration Observations. 



Log r 



9 -15621 

 9 -15610 



a. m. t. 



h. m. 

 3 07 

 3 19 



a. m .t. 



h. m. 



2 57 



3 24 



a. m. t. 



h. m. 

 2 10 

 2 22 



Temp. Time of the vibration, 



o sec - 



74-6 4 -4231 . . . 



74-6 4 -4230 . . . 



Log raX. 



-33899 



October 2. 1878. — Deflection Observations. 



Temp. 



Distance of centre 

 of magnets, 

 ft. 



1-0 . . 64-7 

 1-3 . . 64-7 



Observed 

 deflection. 



o / // 



16 21 33 

 7 22 11 



Vibration Observations. 

 Temp. Time of the vibration. 



sec. 



61-7 4 -4399 . . . 



61-7 4-4400 ... 



Log. ™ 



5 X 



9 15174 

 9 -15153 



Log mX. 

 -33458 



