ECLIPSE OP THE SUN, NEAR OLMOS, PERU. 



17 



If y^ the angle which the axis of the cone forms with its side, and 



c =^ the perpendicular distance of the vertex of the cone from the plane x, i/, 

 we shall have 



sinf^ — ; — (sin h — ksinn') (for internal contact) 



k 



c = z — (for internal contact) 



sin f 



c tang f^= I 



according to Burckhardt's tables of the moon, the radius of the moon, or A- ^0.2725, 

 and the mean radius of the sun, or h= 15' 59". 788 (Bessel). Therefore: — 



log {sink — ksinn')^^ 7.6666903 (for internal contact), and 



Assumed longitude of place of observation =; 80° ^ 5'' 20" 



1st internal contact. 



T = assumed corresponding Greenwich m. t. of observation 



Xa = corresponding values 



2/„= " "... 



Xj = hourly variation of x . 



y,= " " 2/ . . _. 



© = sideral time at instant of observation 



a = corresponding values 



rf = " "... 



if' = geocentric latitude of place of observation 



log p = log earth radius .... 



2(1 internal contact. 

 Qh. 51m. 



—0.9055260 

 —0.1487045 

 + 0.4893457 

 —0.2642366 

 89° 59' 10".00 99° 14' 19".95 



165° 47' 37".83 

 6 4 50.04 

 5 57 37 

 9.9999843 



The co-ordinates of place of observation are : — 



^ ^ p cos ^' sin (0 — a) 



)7 = p j cos d sin ^' — sin d cos ^' cos (0 — a)\ 



^ = p J sin d sin ^' + cos d cos ^' cos (0 — a)\ 



and the computed values : — 



First internal contact 



I = —.914188 

 ^ —.144740 



J +.378473 



Assuming vi sin M = x^ 



m con M = 2/o — 1? = 

 11 sin N = x^ 

 n cos N = y^ 



Second internal contact. 

 —.912450 

 —.145167 

 + .382480 



First. Second. 



? = +.008662 +.006924 



-.003964 —.003537 



+ .4893457 

 —.2642366 



and \l — 2, tangf\ sin ^ = m sin (M—N), 

 3 



