There, as in every settlement in Central America, the eaves of the dwellings were lined with Turkey buzzards. These huge birds are regarded with something akin to veneration. They are never molested; indeed, like the pariah dogs of the Orient, they have the right of way; and they are evidently conscious of the fact, for they are tamer than barnyard fowls. They are the scavengers of the tropics. They sit upon the housetop and among the branches of the trees, awaiting the hour when the refuse of the domestic meal is thrown into the street. There is no drainage in those villages; strange to say, even in the larger cities there is none. Offal of every description is cast forth into the highways and byways; and at that moment, with one accord, down sweep the grim sentinels to devour it. They feast upon carrion and every form of filth. They are polution personified, and yet they are the salvation of the indolent people, who would, but for the timely service of these ravenous birds, soon be wallowing in fetid refuse and putrefaction under the fierce rays of their merciless sun. In the twilight we wandered by a crescent shore that was thickly strewn with shells. They were not the tribute of northern waters: they were as delicately fashioned and as variously tinted as flowers. All that they lacked was fragrance; and this we realized as we stored them carefully away, resolving that they should become the nucleus of a museum of natural history as soon as we got settled in our California home. We had crossed the Isthmus in safety. Yonder, in the offing, the ship that was to carry us northward to San Francisco lay at anchor. For three days we had suffered the joys of travel and adventure. On the San Juan river we had again and again touched points along the varying routes proposed, by the Maritime Canal Company of Nicaragua and the Walker Commission, as being practical for the construction of a great ship canal that shall join the Atlantic and the Pacific Oceans. We had passed from sea to sea, a distance of about two hundred miles. The San Juan river, one hundred and twenty miles in length, has a fall of one foot to the mile. This will necessitate the introduction of at least six massive locks between the Atlantic and the lake. Sometimes the river can be utilized, but not without dredging; for it is shallow from beginning to end, and near its mouth is ribbed with sand-bars. For seventy miles the lake is navigable for vessels of the heaviest draught. Beyond the lake there must be a clean-cut over or through the mountains to the Pacific, and here six locks are reckoned sufficient. Cross-cuts from one bend in the river to another can be constructed at the rate of two hundred and fifty thousand dollars, or less, per mile. The canal must be sunk or raised at intervals; there will, therefore, at various points be the need of a wall of great strength and durability, from one hundred and thirty to three hundred feet in height or depth.