HUNTER'S OBSERVATION OF EGRESS, AT SUEZ. 335 



than mine by 13 9 '66. I estimated true contact at 13 h . 27 m . 37 Sl 65, the black 

 drop being then well marked, and as dark as the body of the planet, cusps 

 being observed well marked at 13 h . 29 m . 10 s -65. These times are corrected 

 for clock error and rate. 



The rim of silvery light round the edge of Venus on leaving the Sun's 

 limb was very beautiful and striking, but as soon as I saw that it belonged 

 to the planet, and likely to last a considerable time, I commenced measuring 

 cusps with the double-image micrometer. I obtained 8 measures of the 

 diameter of Venus, 25 distances of limbs, and 75 cusp measures, the whole 

 of which I regret to say proved useless, as, in determining afterwards the 

 value of the screw of the double-image micrometer, I found it totally 

 untrustworthy, as already reported to you.* 



The time noted for last contact is very uncertain, the undulations of the 

 Sun's edge being then very great (all cloud had just cleared off the Sun), so 

 that the time noted is that when I found myself certain the notch did not 

 recur, and is consequently too late probably by 5 s . or 10 s . 



Transit observations, the telegraphic comparison on the 14th, and the 

 necessary reductions, occupied my time until December 24, when I was 

 enabled to pack up my instruments and hut ready for shipment. 



At Suez the Equatorial was situated 11 feet 9 inches due West of the 

 Transit instrument. From the latter to the nearest (S.E.) corner of the 

 Chalet the distance was 91 feet 8 inches ; to the Flagstaff, 48 feet 6 inches. 



Details of the Observation of Egress. 



Times of Phenomena of INTERNAL CONTACT, recorded from the Sidereal 



Chronometer Losebtj 102. 



h ui s 



13. 26. 34, Fig, 1, Plate XI. Just a line, no more. 

 13. 27. 19, Fig. 2, Now well marked. 



13. 28. 52, Fig. 3, Cusps well marked. 



EXTERNAL CONTACT. 



13. 56. 15-0. The notch has now become undiscernible. 

 I tried to get measures several times between this and the last observation, 

 but the boiling of the Sun's edge from the atmosphere was nearly as great as 

 the planet's notch, if not quite so. 



* Mr. Hunter's micrometer measures have, in consequence, not been published. 



