Intelligence and Miscellaneous Articles. 

 The following Table sums up the results obtained * : 



477 



Lines of 

 the spec- 

 trum. 



X. 



1st series. 



2nd series. 



Value of the 

 angle of rotation. 



Angle of 

 rotation. 



Number 

 of obser- 

 vations. 



Angle of 

 rotation. 



Number 



of obser- 

 vations. 



Defini- 

 tive. 



Calcu- 

 lated. 



Differ- 

 ence. 



A 



a 



760-40 

 718-36 

 686-71 

 656-21 

 589-51 

 588-91 

 526-96 

 486-08 

 430-72 

 410-12 

 396-76 

 393-29 

 381-96 

 372-68 

 358-05 

 343-97 

 336-02 

 328-56 

 317-75 



o 

 14-293 



21-729 

 32-737 



47 V 518 

 51-208 



55-712 



58-918 

 64-459 

 70585 

 74-574 



78-582 

 84-972 



40 



16 



14 



50 

 16 



20 

 50 

 30 

 30 

 20 

 50 

 37 



12-668 

 14-304 

 15-746 

 17-318 

 21-684 

 21-736 

 27-543 

 32-774 

 42-604 

 47-481 

 51-178 

 52-155 

 55-539 

 58-844 



20 

 20 

 20 

 20 

 20 

 40 

 20 

 20 

 20 

 20 

 20 

 20 

 20 

 30 



... 



12-668 

 14-304 

 15-746 

 17-318 

 21-684 

 21-736 

 27-543 

 32-774 

 42-604 

 47-499 

 51-193 

 52-155 

 55-625 

 58.881 

 64-459 

 70-585 

 74-574 

 78-582 

 84-972 



12-742 

 14-337 

 15-746 

 17-314 



21-689 



adopted. 



27-530 



32-752 



42-634 



47-514 



51-151 



52-165 



55-701 



58-878 



64-480 



70-684 



74-598 



adopted. 



84-960 



+0°074 

 +0-033 



o-ooo 



-0-004 

 +0-005 



-0-013 

 -0-022 

 +0-030 

 -0-015 

 -0-042 

 +0-010 

 +0-076 

 -0003 

 +0-021 

 +0-099 

 +0-024 



-0-012 



B 



...... 



D, 



£ 2 



E 



F 



G 



h 



H x 



£ :::::: 



M 



N , 







P 



Q 



E 



We have adopted as the definitive values the means of the obser- 

 vations of only the first series for the lines A to Gr, the means of 

 both series for the lines from h to M, and the numbers of the second 

 series from N to R. For broad lines and those which form part 

 of a complex group, such as A, H 1? H 2 , L, we reckon that these 

 values are within o, l of being exact ; the approximation must be 

 to o, 05 for the other lines from atoN; the closeness then dimi- 

 nishes ; but the deviation from accuracy does not exceed 0°-l for E-. 



The values in the eighth column were calculated by the formula 

 of Boltzmann, 



B^ C 



^~10 6 A 2 + 10 l2 A 4 ' 



in which the values of the constants, deduced from those obtained 

 by experiment for the lines D : and Q, are 



B = 7'111540, C=0-148061. 



* The wave-lengths adopted, as set down in the second column of the 



o 



Table, are those of Angstrom from A to k, those of M. Cornu from H x to 

 O, those of M. Mascart from P to R. The angles of rotation, .in the third 

 and fifth columns, in degrees and fractions of a degree, are the mean 

 values of a number of observations, indicated in the fourth and sixth 

 columns. The seventh column gives the values of the angles of rotation 

 adopted as definitive ; the eighth column, the same values calculated by 

 Boltzmann's formula ; the ninth column, the difference between the results 

 of the calculation and those of experiment. 



