Again there followed a series of schemes for canal construction at various points of the isthmus. For example, Dr. Edgar Cullen created some excitement in England in the early Victorian days by giving a very favourable account of the Caledonian route across the isthmus at Darien, in a lecture to the Royal Geographical Society. The doctor was received by the young queen and the Prince Consort, a corporation was formed, and an engineer sent out to make surveys from Caledonian Bay. A British and a French man-of-war were dispatched to the isthmus to make investigations. But the surveyor was driven from Caledonian Bay by local tribes, and so went on to Panama, giving a favourable report of that route on his return to England. But nothing came of these incidents, and the American Civil War in the early 'sixties diverted the attention of the United States from isthmian affairs. At the end of the war American interest revived, and public opinion set more and more against the idea of sharing a canal with any other Power. In 1869 President Grant gave the first public expression to the demand for an American canal under American control. "I regard it," he said, "as of vast political importance to this country that no European government should hold such a work." Later, in an article in the _North American Review_, he said, "I commend an American canal, on American soil, to the American people." Just before the President's declaration of policy the United States had concluded an important treaty, known as the "Dickinson-Ayon Treaty," with Nicaragua, securing a right of way for a canal over the Nicaraguan route; and, just afterwards, President Grant appointed an Interoceanic Canal Commission which investigated four routes for a canal, and finally, in 1875, reported unanimously in favour of the Nicaraguan route from Grey town to the San Juan River, to Lake Nicaragua, through the Rio del Medio and Rio Grande valleys, to Brito on the Pacific coast. In 1869 an event occurred which was to have a very decisive effect on isthmian affairs--the opening for traffic of the Suez Canal. These two isthmuses in the eastern and western hemispheres have some obvious features in common. They both link two vast continents and form a barrier between two oceans or oceanic systems. They are fairly equal in breadth--Suez, sixty miles, and Panama about fifty-four. The shortest line across each runs almost exactly north and south. And they were both until recent times uninhabited country. But there are many dissimilarities. The isthmus at Suez is a flat and sterile desert; that at Panama is hilly and covered with an almost impenetrable jungle of tropical vegetation. Again, Suez is a healthy district, whereas Panama was, until recent years, a pest-house as deadly as Sierra Leone or the Guinea coast. Mr. Bryce in his charming book on "South America" compares these two inter-continental causeways from a more historical point of view. He writes:--