1880-1920] ROYAL ASTRONOMICAL SOCIETY 247 That the publications of the Society have been the means of making a great many observations public property is an undoubted fact. But the fulfilment of the second promise was never even attempted. It included " the formation of a complete catalogue of stars and of other bodies, upon a scale infinitely more extensive than any that has yet been undertaken, and that shall com- prehend the most minute objects visible in good astronomical telescopes." Five years after the issue of this manifesto, Bessel invited the co-operation of observers to construct star maps of the region between 15 Declination. This was only a small portion of the heavens, yet the work took thirty-four years to complete. On the other hand, when Argelander took in hand the construction of similar maps of the whole northern hemisphere, based solely on new observations, he and two devoted assistants completed their great task in eleven years, including the printing of a great atlas and a catalogue in three volumes of 324,000 approximate star places. The desire was at once expressed that this work might be continued to the South Pole, and several southern observatories were to divide it between them. But nothing came of this project ; while Schonfeld alone in a few years continued the work to 23 Declination. Again, the great undertaking of the Astronomische Gesellschaft, the catalogue of all stars down to the ninth magnitude from zone observations, took for the northern hemisphere more than forty years to finish, chiefly because " On the strength of one link in the cable Dependeth the might of the chain," and there is generally more than one faulty link in co-operative chains. This has also been the case with the photographic chart of the heavens, while Gill and Kapteyn rapidly carried out their photographic continuation of Argelander's and Schonfeld's work. There seems, therefore, no reason to regret that our Society has never wasted time and energy in organising co-operative under- takings. Again and again history has shown that what is wanted for a successful undertaking in practical Astronomy, as in every other great and laborious undertaking, is the proper kind of man for the work. If he be found and be given the material means necessary for the realisation of his ideas, he will carry out the work far more quickly and perhaps better than a dozen people acting under instructions from a central institution could com- plete their tasks. And this is not only the case with charts and catalogues of stars. The planetary tables of Le Verrier and
