QUESTIONS of the organisation, the objects, and the activities of the Carnegie Institution of Washington are of widespread interest. The demand, indeed, for popular and technical information concerning this institution is far greater than the available supply. It should be stated, however, that it is not practicable to explain in any brief compass the history of the development of so novel an establishment. There has been scant time thus far for those engaged in this development to step aside and write anything but an abstract of current events. It should be stated also that the complexity of the subject is much greater than might appear to casual observation. The institution has recently issued the eighth of its series of year-books, or annual reports. These year-books contain upwards of two thousand pages of condensed history, and when one considers that they embody what is probably the most complicated miscellany of contemporary literature, it may be seen to be no easy matter, even if one had the time, to gain first-hand knowledge by reading these books; and it may also be seen to be no easy matter even for one participating in their publication to give a comprehensive summary of their contents. Only the barest-outline, therefore, of this history can be given in the present article, while some major and many minor considerations of interest doubtless to individuals may be referred to only casually or not at all.