158 ON THE VISIKILITY OF VENUS — CAMERON. 



two about a (juarter of an hour before sunset, — before sunset not 

 after. She looked bright enough to be good for tln-ee or four 

 evenings yet, if tlie clouds or fog would only let her througli. 



At Marseilles the skies were clearer then, and M. Bruguiere 

 got his last glimpse of her on the 27th, five days later than mine- 

 At what time of the day I don't know, l>ut as he counts it four 

 days (instead of three) before conjunction, I think it must have 

 been early in the day and probabl}^ about noon. In his longi- 

 tude the time of conjunction was 2 a. m on Ma}' 1, so his obser- 

 vation could not very well be more than B| days before. That 

 is the closest in point of time that I know of. The elongation 

 for Greenwich noon on the 27th was 7f "^, the phase less than ,J,j, 

 and the brilliancy only 6.9. He succeeded in holding her again 

 until about 4^ da3's before the last inferior conjunction in 

 December 1890, and though the elongation was then nearly 9°. 

 tlie phase was a little less than before, — | of ,1, only, — and tlie 

 brilliancy was only 6.5. In smallness of phase and lowness of 

 brilliancy this is the very best of all the observations that I have 

 a record of, and it is probably as good as can be done. If any 

 one cares to try to equal or better it, the first week in July will 

 afford an opportunity to do so if the weather permits. 



Perhaps it may be as well to collect into a couple of sentences 

 the three or four chief facts mentione<l above. 



Venus's last complete season as evening-star began with the 

 superior conjunction of February 18, 1890, and ended with the 

 inferior conjunction of December 4, in the same year, lasting for 

 a period of 290 days. I saw her with my naked eye as early as 

 March 16, 26A days after superior conjunction, and M. Bruguiere 

 saw her (in the same latitude) with his naked eye as late as 

 November 29, 4J days before inferior conjunction ; so she was 

 visible to the naked eye during that season on 259 days, that is, 

 on 89 days out of 100. When I saw her first in March she was 

 only 6| distant from the sun's centre , when M. Bruguiere saw 

 her last in November the brilliancy was only (ik per cent, of her 

 mean greatest brillianc}'. 



There is no reason why as good, if not a better, .slK)wing could 



