a 
5 
pared with that from the artificial star. Mr. Dibden has adjusted 
his instrument so finely, that he can diminish the light of his 
artificial star to the two hundred thousandth of a sperm candle! 
I admit that the idea of comparing the light from a star to that of 
a sperm candle does not sound poetic, but it is at any rate a more 
exact style of measurement than the vague phrase of a “star of 
the 1st, 2nd, or 3rd magnitude.” 
Father Perry, to whom I have previously alluded, had for some 
years made most interesting observations on sun spots, whick have 
been decreasing in number for the last three or four years. The 
minimum time is however drawing to a close, and will probably be 
succeeded by a maximum period of disturbance. Father King, 
also of Stoneyhurst, has succeeded in taking on an average 258 
drawings a year of sun spots, and in many respects they are con- 
sidered more reliable than photographs, The area of the san 
spots sometimes changed as much as one hundred million square 
milesinaday. Father King suggests that the sun spots may be 
caused by meteoric streams. 
Mr. Isaac Roberts has, as usual, done good work in his admir- 
able photographs of nebule. His photograph of the nebule in 
Andromeda shows that it is a bright central mass, surrounded by a 
stream of nebulous matter, spiral in form. The 81 Messier nebule 
shows a spiral formation, and many bright starry points on the 
spiral streams. The 51 Messier nebule also shows a spiral struc- 
ture, and lines of stars seem to follow the line of the spiral streams. 
These photographs are considered so wonderful, that they have 
been alluded to as a ‘“‘ new cosmical revelation.” 
Mr. Stanley Williams has made some interesting observations on 
the planet Jupiter, and has systematically noted the changes in 
those spots and markings which were sufficiently distinct for the 
purpose. The red spot, which was so conspicuous in 1887, had 
become much paler, but the red tinge is still visible; its period of 
rotation is nine hours, 55 minutes, 40 seconds. 
On the 20th September last there was a closer conjunction of 
Mais and Saturn than at any period during tle last six thousand 
years. Thatis to say the two planets were almost in the same 
longitude, their centres being not more than 55 seconds apart, so 
that to the naked eye they appeared as but one orb. 
It is no uncommon event for Mars and Saturn to be in line, but 
the interest on this occasion was in the smallness of the iaterval 
which apparently separated them. And on the 26th of the same 
month, another rare occurrence, known to astrologers as ‘ ‘Trigon,’ 
took place, in other words Venus-passed within little more than 
the moon’s diameter of Mars and Saturn. A ‘Trigon’ can only 
oceur once in about 200 years, the last time being in 1603, when 
~ilz 
