284 



PROFESSOR MILLER, ON SPURIOUS RAINBOWS. 



A fourth series of observations was made with a smaller cylinder of 

 water, the diameter of which is rather uncertain, the tube having been 

 accidentally broken before the observations for determining the diameter 

 of the stream were repeated. At the commencement of the observa- 

 tions it was found that m = 1.33453 ; at the conclusion it was found 

 that p = 1.3348. This shews that either the prism or the stream had 

 been displaced in the interval. The comparison of the observed and 

 theoretical radii has been made with both values of l x. The former of 

 these agrees best with the theory. 



(E) 



Primary bow. If M = 1.33453, 4 <£' - 2 (p = 41°.52'. If M = 1.3348. 

 4 0' — 2 <p = 41°.49'. Diameter of the cylinder of water = 0.0135 inch. 



Limit 



Brightest 



Dark band 1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14. 



15 



16 



17 



18 



19 



20 



21 



22 



42° 



41 



40 



39 



38 , 



37 



37 



36 



35 



35 



34 



34 



33 



33 



32 



32 



31 



31 



31 



30 



30 



29 



29 



29 



68' 

 18 

 34 

 28 

 38 

 52 

 12 

 34 

 56 

 23 

 51 

 20 

 49 

 21 

 53 

 26 

 58 

 34 

 9 

 44 

 20 

 56 

 30 



77 

 30 

 34 



29 

 40 

 53 

 13 

 35 

 58 

 25 

 53 

 21 

 50 

 24 

 55 

 32 



64' 



17 

 32 



29 

 38 

 53 

 12 

 31 

 61 

 29 

 53 

 22 

 52 



55 



48' 



19 



34 



31 



39 



53 



14 



34 



61 



27 



