Reduction Formula and Instrumental Constants 255 



attachments follow the inclination corrections; the declination corrections adopted for 

 the compass attachments of the sea dip-circles are given on page 256. 



Universal magnetometer I4. — Universal magnetometer 14, designed and constructed 

 by the Department of Terrestrial Magnetism, was used during April to September 1913 on 

 Cruise II. The adopted inclination-corrections are given in Table 64. 



Table 64. — Inclination Corrections foT Universal Magnetometer I4. 



Universal magnetometer 19. — Universal magnetometer 19, designed and constructed by 

 the Department of Terrestrial Magnetism, was used during September 1912 to May 1913 

 on Cruise II. The adopted inclination-corrections are given in Table 65. 



Table 65. — Inclination Corrections for Universal Magnetometer 19. 



Land dip-circle 178. — Circle 178, manufactured by Dover, was used during Cruise I. 

 While on board the Carnegie the needle pivots deteriorated rapidly, so that very few avail- 

 able results were obtained. The adopted inclination-corrections are those determined 

 from least-square adjustments of data obtained during 1908 and 1909, prior to the Carnegie 

 work, and are given by the formulae: 



Needle 1 FA/ = -f-0:2+0:4 cos 7 -t-0:5 sin 7 



Needle 2 FA7 = +0.3-0.4 cos 7 -0. 1 sin 7 



Needles T'M = +0.2-1 .0 cos 7 -fO.3 sin 7 



Needle 6 7'A7 = +0.4+1.2 cos 7 +0.3 sin 7 



The adopted correction for observed declinations by the compass attachment is +l!2. 



