The Transit of Mercury on November 12, 1861. 71 



A PLANET S SHADOW. 



The Shadow of the Planet Mercury, and of a group of solar spots, as shown on a 

 sheet of paper during the Transit of Mercury, Nov. 12, 1861, 8.30 a.m. 



THE TRANSIT OF MERCURY ON NOV. 12, 1861. 



BY THE HON. MES. WARD. 



" A transit of Mercury will happen on the morning of Nov. 

 12th. . . . The planet, at sunrise, will appear on the sun's 

 disc, as a perfectly round and intensely black spot." So said 

 the almanacs for 1861; and no doubt more than one possessor 

 of a telescope added the query, not to be answered for nearly a 

 year, — " Shall J see it? will fine weather, a favourably situated 

 horizon, and personal life and health, combine to give me the 

 pleasure of seeing a phenomenon which has not occurred for 

 thirteen years, and will not, after this transit, occur again for 

 seven years to come ?" * 



Such were my thoughts on being reminded that the transit 

 of 1861 was coming, and no longer to be looked on as an event 

 in the remote future. Time passed on its stormy way; the 

 grand comet of June came unannounced, and disappeared in 

 the distance; and November 12th found me surrounded by 

 many favourable circumstances for viewing the transit. I was 

 absent from home, but had borrowed an old and rather good 



* The transits of Mercury which have occurred during the present century, 

 were in the years 1802, 1815, 1822, 1832, 1835, 1845, 1848, and 1861. Those 

 still to occur, will be in 1868, 1878, 1881, 1891, and 1894. They occur either in 

 May or November, since, from the position of the orbit of Mercury, the planet can 

 only pass between the earth and the sun, and near enough to aline joining the two 

 bodies, to be seen upon the solar disc, in one or other of those months. (See 

 Johnston's " School Atlas of Astronomy.") 



