586 REPORT— 1901. 



at very short notice, I shall not attempt, nor would you expect, a formal address 

 such as we hoped to hear from him ; but I will venture to put before you one 

 or two reflections on a topic which has been much before my attention during the 

 last few years because directly connected with my own work, and which has a 

 special interest for us from the allusions made to it yesterday morning by the 

 President of our Section, viz., the question of scientific co-operation. It is a 

 matter of considerable importance to astronomers, who have to deal with 

 numerous observations and calculations ; indeed, the millions and billions which 

 express the distances, sizes, or ages of the heavenly bodies, and which are used 

 to such good purpose by some lecturers for startling the imaginations of their 

 audiences, scarcely surpass the numbers which must be used to express the work 

 to be done by an astronomer. The enterprise on which we are engaged at the 

 Oxford University Observatory at the present moment is the measurement of a 

 quarter of a million star-places, which will take us about seven years; and we 

 are only one of eighteen observatories co-operating in a scheme of work. The 

 product of eighteen by a quarter of a million does not bring us near the 

 billions; but if we are minded to produce big numbers we might remember 

 that in the determination of each individual star-place a good many figures 

 are required. At Oxford we try to keep the number to the irreducible minimum, 

 but it certainly exceeds thirty even there ; while at other observatories it 

 reaches 800 or 400. Thus we can with ease secure a creditable position in the 

 thousands of millions in respect of this one piece of work, and the lapse of a century 

 or two is all that is necessary to produce billions of figures in the ordinary course 

 of astronomical observation. It is clear that in such work co-operation is an all- 

 important factor, and the study of the best means for securing it and for using it 

 when secured may well claim a share of our attention. 



I may pause for a moment to consider the possibility that our experience may 

 be of value to the devotees of other sciences. ' Other sciences,' said Major Mac- 

 Mahon yesterday, ' are not so favourably circumstanced as is Astronomy for work 

 of a similar kind undertaken in a similar spirit.' But what maybe true to-day 

 may not be true to-morrow. It was not astronomers, but mathematicians, who 

 first showed the value of a certain kind of co-operation. Major MacMahoa 

 reminded us that the Spitalfields weavers founded a mathematical society in 1717, 

 and thus anticipated by more than a century the formation of the Astronomical 

 Society in 1821, which ultimately absorbed itn prototype. Possibly in the future 

 mathematicians will find the need of co-operation of this other kind, which consists 

 in sharing a great piece of work among several workers for the sake of comfort and 

 rapidity, and so may profit by our example, as we formerly profited by that of 

 the Spitalfields weavers. And there are indications that in another science, 

 that of Zoology, the time may be close at hand when co-operation between 

 workers, of a type very similar to that in full swing in Astronomy, will be a 

 boon, if not a necessity. Professor Karl Pearson, Professor VVeldon, and others 

 are introducing into zoology numerical operations on a large scale, which 

 promise further and further increase; and they would no doubt be ready to 

 indicate even now enterprises of a valuable kind which they are only deterred 

 from undertaking by their magnitude, and which a suitable scheme of co-operation 

 might bring within the range of practical politics. Hence we should look to our 

 methods of work in Astronomy with the responsibility attaching to those who are 

 leading where others may follow ; and above all things take care to make clear 

 any mistakes we have made, so that others may perhaps profit by our expei-ience. 



If it seems invidious thus to emphasise our mistakes, I would remind you that 

 astronomical co-operation has not always been successful ; indeed, it has very 

 often ended in failure. I do not mean simply failure to attain its object. The 

 band of astronomers who divided the sky between them at the end of the eighteenth 

 century to look for a minor planet met with this kind of failure, for the first dis- 

 covery fell by the irony of Fate to another, who was not engaged in any special 

 search of the kind. This unlucky accident must not, however, make us forget that 

 the co-operators worked diligently side by side for several years. Failure of a 

 more real kind has overtaken enterprises to chart the stars or to map the Moon, 



