A SOUTHERN OBSERVATORY. 125 
put upon them. They will be pursued gravely, systematically, by the 
concerted efforts of successive generations, through the toil of innu- 
merable unpretending workers guided to effectiveness by the highest 
jntelligence of the times. A measure of success is, under these circum- 
stances, certain, and even a small measure of success in this direction 
will suffice to broaden and deepen the channels of all future human 
thought. 
Hence the profound significance of the decisions of the Paris Congress, 
by which an international scheme for photographically charting the 
heavens and cataloguing a large proportion of their contents was set 
on foot. Fortunately for its own reputation our Government, after 
long delay, has adopted what might have seemed the foregone conclu- 
sion that a share in this work is England’s right and duty, and has au- 
thorized the construction of the requisite instruments for Greenwich and 
the Cape. Before another year has elapsed they will be mounted in 
their respective places and the recording process, to be carried on simul- 
taneously at fourteen or fifteen observatories in every part of the world, 
will have begun. 
Meanwhile Dr. Gill, to whose initiatory energy the approaching reali- 
zation of this great plan is due, has almost completed a preliminary task 
of vital importance to its due accomplishment, as well as to sidereal 
science in general. One of the most famous achievements of recent as- 
tronomy is the “Bonn Durchmusterung,” a list of 324,000 stars from the 
North Pole to 2 degrees south of the equator, observed by Argelander 
at Bonn. Until it was compiled the smaller stars were a nameless 
crowd with no recognized identity. For the purposes of science they 
could scarcely be said to exist. But once 
Set in note-book, learned and conned by rote, 
their changes could no longer elude notice; and detected change leads 
commonly to increased knowledge. A solid foundation was moreover 
laid for the study of sidereal statistics, destined, perhaps, to lead to 
momentous results at no distant future. 
An extension of the “ Durchmusterung” to the southern hemisphere 
was contemplated from the first, but was more easy to contemplate 
than to execute. No southern observatory was in a condition to un- 
dertake a task so colossal. Dr. Schonfeld, Argelander’s successor at 
Bonn, carried, however, the enumeration as far as the southern tropic, 
where it seemed likely to stop, when some surprising photographs of the 
great comet of 1882, projected on wide fields of stars, taken at the 
Royal Observatory with the help of Mr. Allis, of Mowbray, opened to 
Dr. Gill the possibility of completing Argelander’s stellar review by 
this relatively unlaborious method. And the possibility is rapidly 
being converted into an accomplished fact. Two assistants, Mr. C. Ray 
Woods and Mr. Sawerthal, are employed every fine night in expos- 
ing plates with instruments, each consisting virtually of two telescopes, 
one for concentrating upon the plates the rays of the multitudinous 
stars within a field of 36 square degrees, the other for enabling the 
