52 



i> [SC I S S ION U !•' T II E D 1 U K S A L V A R I A T 1 N 



Scale 



(D.)— SoLAR-DirnxAi. Variation of the Horizontal Force ; October to Marcii, 1840 to 1845. 

 divisions. I' 1 = 0.0000365 parts of the horizontal force. 



Nnvenihi'r. 



December 



January. 



February. 



0" 1 2 3 4 5 G 7 8 9 10 11 N. 13 14 15 1G 17 18 19 20 21 22 23 24" 

 Philadelphia mean time. 



Table VI. contains the coefficients i?, B, B 3 B 4 of the general equation:— 

 A, " A + B { sin (0 + C.) + 11, sin (2 + C,) + //, sin (3 + C a ) + B 4 sin (4 + <\) 

 expressed in parts of the horizontal force, by multiplying the corresponding quan- 

 tities in the preceding equations with the value of a scale division. The angles 

 <\ (', C 3 C 4 will be found in Table VII.; they arc the same as given before. 

 increased by 1*0°, so as to make a corresponding change in the direction of the 

 scale readings; increasing numbers will now indicate increasing force. 



