492 Mr. J. Prescott on the 



Hence 



eOTryahv 2 _ aw 90 637xl0 6 Xff 90 



n ~ n ll^"~800xl0 6 x#*ll 



= 6-51, (36) 



since a = 637 x 10 6 centimetres and n = 800x 10 6 grams per 

 square centimetre. 



Let B be written for 1(2 — ^ — -^)A m , and s for 



\ 2 m-\-2J 



■ . Then (34) gives 



n 



. 6-51 f. 10,1 5 



A * = 477^ | B -T Ao j + 4^7~3 



= 0-07750B-0-2583A + 0-011905s. . (37) 



Also equation (35) gives 



6x6-51 f 10 A 3 m 2 + 9m-f-4 A l,„J 



TIT) I " 3 A ^ +2+ 2(m + 2)(m + 7) Awi ( ^ 



A -+6 - ^+4) (m + 6) (m -f 9) (m + 11) I 3 " ni+;i ' 2(m + 2)(m + 7) 



when r/2 is zero or any positive even integer. Putting 

 7n = 0, 2, 4, 6, &c. in turn in this equation we get 



2-17 r 10 A 3 



A,= 



{-yA 2 + 7 A J 



4.3.11 



= 10- 5 {- 5480 A 2 + 704-5 A }, (39) 



6-51 (_10 A 13. i 



^8-8.11.131 y A4+ i2 A2 j 



= 10- 6 {-18970A 4 + 6165A 2 } 



_ 10-6{-1469B + 4886A +6165A 2 -225-7.9}. (40) 

 The last line is obtained by using the value of A 4 from (37). 

 6-51 / 10 A 14 I 

 Al ° " 10.13.20 I " 3" 6 + n A4 | 



= 10- 6 {247B-883A + 458A 2 + 38-0 5 } 7 . . (41) 



A 6*51 r 10 141 . ] 



Al2 -20.15.17l~ y A8 + i04 A6 j 



= 10- 7 {62-5B-86A - 1211 A 2 -f 9-64, . . (42) 



_ 6-51- r 10 7 | 



Al4 ~ 2TT47T77I9 I " "3 10 + 5 As J 



= 10- 7 {-21B + 70A + 51A 2 -3-24, . . . (43) 



6-51 r 10 97 i 



Al6 ~ 7 . 16 . 19 . 7 I "T 12 + 68 10 J 



= 10- 8 {14B-54A + 46A 2 + 2-l 5 }. . . . (44) 



