and on Astronomical Refractions. 505 



c -' + V <* c-**' -^ c 5h> c~ Zx ' 



' 



= c*' /r*' - 2 A' c 2/t/ c- 2 *' -I- ' c 3/ ' / c - s * / 



f-i 2 



The first part of the refraction is given by the expression 



r~ ^rf^ 



(I + ) sin / x . d<r = 



./ o ^cos 3 + 2 ' x' 

 Let 



= z 2 



cos 2 fl 2 z d 



7 d j? = 



/: 



-22 



+ 2 i' a, J ~~ Vg i' Vn / c d z 



z' 



At the horizon cos = 0, z' = 



2 ' 



This part of the horizontal refraction 

 !+ ^ f if f 2h<c 2/t ' 3*h 



j 



H 



1.3 3 A 2 2.3 22 A^ 33 A 



~ 



.2 



2.3.5 J 23A3 



2 ' 2 1.2 



32.5 33 43 



"" 



2.2 



