VENUS IN DAYLIGHT — CAMERON. 357 



other conditions are nearly at their worst. This was her altitude 

 when my opera glass (N.) showed her on the afternoon of infe- 

 rior conjunction in July, 1892. 



I have several times tried, both with eye and with glass, how 

 ■close to the eastern horizon I could catch her, and how close to 

 the western horizon I could hold her in daylight. These obser- 

 vations were made at tiaies when she was too easy at meridian 

 passage to make it at all interesting to observe her in this way 

 then. The best observations of this kind that I have were made 

 near the greatest elongation that preceded the inferior conjunc- 

 tion of 1892, and near the greatest brilliancy that followed it- 

 At the station where I usually do my observing it is not possible 

 to see as close down to the horizon on the east side as on the 

 west. (Of course, by ' horizon' here, I mean the great circle 90^ 

 distant from the zenith.) Then there is this other difficulty 

 about making very low ol)servations on the east side, — the object 

 is lowest when first found ; whereas, on the west side, you can 

 hnd it when fairly high, and follow it down until it fades out 

 among the denser strata of atmosphere close to the horizon. 



With the eye I have no observation on the east at a lower 

 altitude than 18". This was at greatest elongation on April 

 30, 1892. The elongation was 45^, the brilHancy 70; and 

 the observation was of course a very easy one. At the time it 

 was made, 9.30 a. m , the sun's altitude was nearl 44°. On the 

 west I have done better. With the sun at an altitude of 39°, 

 I found it quite easy to pick up Venus when she was 12|^° 

 high. The date was August 23, 1892. The elongation was 

 43°, a little less than on April 30 ; but the brilliancy was 

 greater than then, being 91. The hour was 3.30 p. m., and for 

 nearly half an hour after this there was no difficulty in repeat- 

 ing the observation. I got my last eye-glimpse at 3.55 when 

 Venus was 8*^ high and the sun 35|'^. 



I have no opera glass observation of this kind, but I may as 

 well set down here the best ones made so far with the field 

 ^lass described above. It found Venus readily enough when 

 *7^^ above the east horizon at 8.35 a. m. on March 28, 1892, a 

 month before greatest elongation. The sun's altitude was then 



