262 Chronicles of Science. [April, 



thickness miglit be repeated if any doubts still remain as to their 

 correctness. 



He remarks in conclusion, " No difficulties exist in photo- 

 graphing a transit of Venus; the operations are quite the same 

 as those practised daily at the Kew Observatory ; no strain on the 

 nerves would occur as in the anxiety consequent on the desire of 

 rendering available every moment of the short duration of a solar 

 eclipse. All the operations could be conducted with that calm so 

 essential for such a problem as the determination of the solar 

 parallax, and I feel confident in recommending that timely steps 

 should be taken to secure photographic records of the transits of 

 Venus in 1874 and 1882." 



A paper by Mr. A. Marth draws attention to the observations 

 which should be made upon Mars duruig the present opposition. 

 His calculations respecting the presentation of the planet correspond 

 closely with those on which we founded the views of i\rars which 

 appeared in our last Chronicle. Mr. Marth invites observers to 

 send in any drawings they may make or have made of Mars, in 

 order that they may be arranged in the order of their areographical 

 longitudes and latitudes. He proposes so to combine them as to 

 form a new map of Mars. We have very little hope that any 

 ordinary drawings will throw much new hght on the conformation 

 of the Martial continents and seas. Those of Mr. Dawes are so far 

 in advance of anything that has yet been attempted (so far at least 

 as fullness of detail is concerned) that little seems to be promised 

 by the examination of inferior drawings. What seems more hopeful 

 is the fact that new and larger telescopes are now being directed to 

 the examination of Mars by well-practised observers. Amongst 

 others we may mention Mr. Browning, who is now observing the 

 planet on every favourable night with his fine 12-inch reflector. 



Professor Kirkwood remarks respecting the meteor-shower of 

 November last, that its duration was much greater than that of 

 former showers. "As seen in Europe in 1866, and in America in 

 1867, the display was limited to three or four hours. Last 

 November, however, it commenced on the night of the 12th, 

 and had not ceased at daylight on the morning of the 14th. 

 This would indicate considerable irregularity in the thickness 

 of the stream." Regarding the meteor-zone as in a sense the 

 tail of Tempel's comet (Comet I., 1866), wo can understand the 

 peculiarity here referred to, as corresponding to the expansion of the 

 visible tails of comets, with increased distance from the nucleus. 

 Doubtless in a few years this expansion will have attained such an 

 extent, and the meteors will be so far apart, that there will be 

 properly speaking no shower, though meteors will continue to bo 

 comparatively plentiful on the nights of the r2th, 13th, and 14th 

 November. 



