The making of the Panama Canal has greatly appealed to the imagination of the world, although its triumph, in a spectacular sense, was interfered with by the rise of the Great War. Here was a wild isthmus which cut off the Atlantic from the Pacific, Europe from Asia to the west. An isthmus which, whilst it formed a barrier between two oceans, did not, nevertheless, serve as a bridge between two continents: those of North and South America. Its construction is an epic of engineering, and, be it added, of medical skill, for without the latter the former would have been of no avail. What has been picturesquely described as the "Conquest of the mosquito," also the conquest of malaria and yellow fever, enabled this work to be done. Formerly the traveller hurried fearfully from his steamer at Colon by rail across the neck to Panama, and if his journey lay beyond to his steamer at Panama, anxious to leave the deadly region as soon as were possible. Now no such anxiety marks his journey. The fight against the natural obstacles to the work--those of climate, of inefficient labour, of mountainous cuttings, of floods, of finance and political intrigue, and all else, was brought to an end--or mainly so--in November 1913, four hundred years after Balboa's dramatic discovery of the Pacific from the "Peak in Darien"; when a vast concourse of people witnessed the great explosion that blew up the last barrier, and a small steamer, the little French steamboat _Louise_, which, twenty-five years before had conveyed de Lesseps to turn the first sod, passed completely, on its own keel, across from Atlantic to Pacific waters--an act of American courtesy to France. Several lessons were learned by the construction of the Panama Canal. One was that corruption and inertia among officials will ruin all effort, as it did with the French--who, however, did very valuable work on the Canal. Another that, with modern appliances and just methods, even so stupendous a work could be carried to success, even in the face of enormous natural obstacles; that the obstacles raised by Nature are less formidable than those man raises himself. Another lesson was in the methods of overcoming the dreadful tropical diseases of yellow fever and malaria. The last lesson was in the treatment of labour, in this case that of the negro; a matter of much importance to all tropical lands, which may justify here a few words.