fauna--notably, in the last connection, the problem of the resemblances which have been observed between Antarctic and Arctic forms of life. CHAPTER XIV. THE NINETEENTH CENTURY AND AFTER; EVOLUTION AND PROGRESS OF GEOGRAPHICAL SCIENCE As during a long period in the history of geography it was usual to limit the connotation of the term, so, when a wider connotation came to be recognized, there naturally followed the creation of certain clearly-defined departments of study under distinguishing titles. The whole structure of geography rests upon two great pillars--upon exploration and upon measurement. With the main lines of exploration we have dealt in preceding chapters, and we have carried that part of our history which deals with precise measurement down to the close of the eighteenth century and the institution of the ordnance survey of Great Britain (Chapter X.). The early part of the sixteenth century witnessed the birth of accurate land-measurement; the early part of the nineteenth its re-birth as a function of organized state-administration. The Indian trigonometrical survey, with which the names of Col. W. Lambton and afterwards Sir George Everest are associated, was begun in 1800; a famous survey of Switzerland, coupled with the name of Gen. H. Dufour, was undertaken in 1809, one of Austria-Hungary in 1816, one of France in 1817; what is now the territory of the German Empire was already fairly represented on local maps when a general survey was undertaken in 1878. Indeed, all European countries may be said to be completely surveyed except certain of the Balkan States, though Russia is much behind in this respect. It must not be forgotten that the processes of close survey are slow: the primary triangulation of Great Britain was only completed in 1858, though the filling-in of details of course proceeded concurrently. And the survey never stands still; there is always revisional work to do. As concerns the British Empire, it has been an unrealized ideal that a territory should be surveyed as soon as possible after occupation, and it was not until 1905 that the defects and lack of system in the mapping of British territories generally were sufficiently widely realized to cause the creation of a Colonial Survey Committee as a central advisory and supervisory body.