You know, of course, that Europe has four landlocked seas, the Baltic, the Mediterranean, the Black and Caspian Seas. The Baltic is enclosed all round by European coasts; the Black and Caspian Seas belong to both Europe and Asia; while the Mediterranean lies between the three continents of the Old World--Europe, Asia, and Africa. Now the Baltic, Black, and Caspian Seas are of about the same size, each having an area about three times that of England and Wales. The Baltic is connected with the Atlantic by several sounds between the Danish islands and Scania. The Black Sea has only one outlet, the Bosporus. The Caspian Sea has no outlet at all, and is really a lake. The Baltic is very shallow, its maximum depth, south-east of the Landsort lighthouse, being 250 fathoms. Next comes the Caspian Sea with a depth of 600 fathoms. The singular feature of this, the largest lake in the world, is that its surface lies 85 feet below that of the Black Sea. This last is the deepest of the three, for in it a sounding of 1230 fathoms has been taken. All three seas are salt, the Baltic least and the Caspian most. Four great rivers enter the Black Sea, the Danube, Dniester, Dnieper, and Don. It therefore receives large volumes of fresh water. But along the bottom of the Bosporus an undercurrent of salt water passes into the Black Sea, which is compensated for by a surface stream of less salt and therefore lighter water flowing to the Mediterranean. The Black Sea is not blacker than any other sea, nor is the White Sea white, the Yellow Sea yellow, or the Red Sea red. And so no faith should be accorded to the story of a captain in the Mediterranean who wished to sail to the Red Sea but went to the Black Sea--because he was colour-blind! But now we can continue our heaving course, still accompanied by dolphins and porpoises. We look in at the harbour of Sebastopol, we anchor in open roadsteads off Caucasian towns, we moor our cables to the rings on the quay of Batum, and finally drop our anchor for the last time at a short distance from the coast of Asia Minor. Proud and bright, with forest-clad heights in the background, Trebizond bathes in the rays of the midday sun. Small rowing-boats come out from the land to take passengers and goods to the quay. The Turkish boatmen scream all together, but no one listens to them. Every one is glad to be landed safe and sound with his baggage. TREBIZOND TO TEHERAN