72 PROF. W. M. HICKS: A CRITICAL STUDY OF SPECTRAL SERIES. 



apparent deviations are the deviations between K.R. and R. I have entered them 

 thus because K.R/s observation errors are entered, and it would be misleading to 

 enter against them. It reproduces the whole of RAM AGE'S results very closely. 

 RITZ calculated from L. and K.R. His difference for P 2 (2), though actually greater 

 than the limit, is probably not due to the form of his formula, but to K.R.'s errors, 

 and should not be counted. 



CsS. Here S 2 (3) is by L., S (3-5) by S., and S (4-7) by R. The values of S (3.4.5) 

 of SATJNDERS corrected to constant v = 553 were used to determine the constants. 

 There are no estimated possible errors to compare with. S (2) by B. gives v = 582'08. 

 If his readings share the error equally, then the difference between observed and 

 calculated wave-length is 74. It is probable that this is chiefly due to imperfection 

 in the formula. RITZ has given 110 formula for this series. 



CsD. The D series differs in Cs from the other elements in the clear possession of 

 satellites, and consequently there are two distinct series to find, D u and D 21 no 

 longer differing by the same amount. The form m = 1 + f gives the best result. The 

 tabulated numbers are those determined for the D n and D 21 series, as the D 21 are 

 always stronger lines than the D 12 . The formula calculated from the D J2 lines (the 

 so-called satellites) differs only very slightly from that calculated from D 21 . They 

 should, of course, be the same (limits excepted). If the values of N/D 2 for m = 1 

 (the top line) be calculated from the two formulae they are found to be respectively 

 17134-86 and 17140-64. They should be the same; their mean is 1713775. The 

 difference between VD n (2) (17040'68) and this is 97'07. The significance will be 

 seen when the additional series are discussed. 



The table also contains the corresponding deviations for the Li spectrum, but the 

 consideration of details is better postponed until that element is dealt with specially. 



The following list of excessive deviations of the formula is excerpted from Table I. 

 only in place of the actual deviations the ratio of the deviation to the maximum 

 allowable is given : 



H. R. H. R. 



LiP(3) 2-3 KP,(5) 2 KPj (5) 1 



LiP(4)2 KP 2 (5) 1-8 KP 2 (5) 4 



LiP(5) 1-6 LiP (5)2 KPj (6) 2 



LiP(6) 1-2 KP, (7 1-2 



NaPi (2) 1 KS (2) 16 



NaPj (3) 2 KS (4) 4 



NaP x (5)l-3 KS (5) 1-5 



NaP!(6)2-2 KS (6) 1-1 



NaS '(4) 2-5 KS (7) 1"! 



NaS (5) 1-3 RbP x (4) 2 



KP, (3) 4 RbS (4) 9 



KP 2 (3) 4 RbS (ft) 10 



KP,'(4)1'6 CsP! (4) 3-6 



