126 A SOUTHERN OBSERVATORY. 
operator to keep them steadily there until their self-portraiture is 
finished. The whole heavens, south of the tropic of Capricorn, will have 
been covered in duplicate by next April, after which only some supple- 
mentary exposures will remain to be made. 
Prof. Kapteyn, of Leyden, is meanwhile busy measuring the plates 
successively transmitted to him from the Cape, and the resulting cata- 
logue—the first derived from photographs—will probably be in the 
hands of astronomers by the year 1892. All stars down to the ninth 
magnitude, and many fainter, will be included in it to the number of 
fully two hundred thousand. This important enterprise is a private 
and personal one. The entire responsibility for it, financial and other, 
is borne by Dr. Gill. 
There is a prospect that before another year has elapsed, the vexed 
question of the sun’s distance will have been definitely set at rest. 
The immediate objects of measurement for the purpose with the 
Cape heliometer, in combination with some other instruments of the 
saine class in Germany and America, are three of the minor planets— 
Iris, in October and November, 1888; Sappho and Victoria during the 
summer of 1889. The position of the planet between successive pairs 
of stars distributed along its path during the favorable period when it 
culminates near midnight will be determined simultaneously from op- 
posite sides of the equator according to a method devised by Dr. Gill, 
so stringent and insistent for accuracy that the errors admitted by it 
must be minute indeed. While celestial surveyors have 270 asteroids 
at their disposal to mark the apexes of their triangles, the long gaps 
of time between the transits of Venus need be of little concern to them. 
To describe the whole of the tasks in progress at the Royal Obser- 
vatory—the cometary work chiefly in the hands of Mr. Finlay, the first 
assistant, the lunar, and planetary observations, the laborious correc- 
tions of star places and star motions—would demand more space than 
is at our command. What has here been aimed at is merely to indi- 
cate the directions in which the activity of the establishment tends to 
expand, and to show that these directions are representative of the 
present, and must be decisive as to the future of astronomy. There is 
room indeed, were the material means at hand, for further expansion. 
In the spectroscopic department the Cape record is still a blank. Yet 
the wise outlay of a few hundred pounds would suffice to set on foot, 
under exceptionally favorable circumstances as to climate and _ situa- 
tion, inquiries into the physical condition of southern stars of extreme 
interest and inevitable necessity. 
There is much to be learned, as well as enjoyed, from a visit to the 
Cape Observatory. Not only the work done there, but the manner in 
which it is done, is impressive. Lessons of earnestness of purpose, 
stability of aim, and cheerful self-devotion can scarcely be missed by 
the itinerant lover of astronomy, in whose mind they will be tempered 
and illuminated by reminiscences of the beauty of flowers by day and 
of the glory of stars at night. 
