graphical societies at home and abroad which number about 50. It is expected also that the leading foreign Governments will appoint delegates, while the Government Survey and Geographical Departments of the leading States of the world will send contributions to the exhibition. It will thus be seen that the London congress may justly be regarded as to some extent semi-official.

It was one great weakness of previous congresses, from the scientific point of view, that the programme of subjects to be brought forward has been left to a large extent to chance, with the result that much time was wasted over matters of trivial importance and of little or no international interest. The organizing committee of the London congress have endeavoured to obviate this objection by arranging as far as possible for the discussion of selected subjects of special importance and of wide and present interest. The general arrangement of the subjects to be brought forward is as follows: —

I. Mathematical Geography.

II. Physical Geography, including Oceanography and Geographical Distribution.

III. Cartography.

IV. Exploration.

V. Descriptive Geography.

VI. Historical Geography.

VII. Applied Geography, including Anthropo-Geography.

VIII. Education.

Under most of these heads definite arrangements have been made for the treatment of certain selected subjects. In each case the subject will be introduced by a paper by a leading authority, to be followed by a discussion in which other specialists are expected to take part. Under Mathematical Geography General J. T. Walker has promised a contribution on Geodesy in relation to the Survey of India, and Colonel H. C. B. Tanner on Photographic Methods in Surveying. Physical Geography is, of course, an important department. Under this head is included Oceanography, which has made vast progress in recent years. It is expected that the Prince of Monaco will take the lead in a discussion on International Co-operation for the Study of the Oceans, to be followed by eminent specialists of various nationalities. Another subject upon which much research has been recently bestowed is Limnology (the science of lakes) and Hydrology (the science of rivers). Pro-