The commander was the first to take the platform; and he appeared with a rose in the lappel of his coat, which probably would not have been there if Mrs. Belgrave had not placed it there. She was very fond of flowers, and had arranged quite a collection of potted plants, as well as filled all the vases on board with cut flowers from the village.
"The subject first in order seems to be the Red Sea; and we have not yet spoken of it in detail, though we have had considerable to say about it. I shall purposely omit some things which will be explained when we come to them. I am glad to see that you have brought your diaries or note-books with you, as I suggested, and you can write down the names of notable sights and the figures I shall give. I wish to say that I have always prepared myself for these occasions, and do not talk to you at random.
"The Red Sea is an arm of the Indian Ocean, with the Gulf of Aden, about 800 miles long, as a connection between them. The Persian Gulf, with the Gulf of Oman, forms a similar body of water, and they will probably render the same service to England and India that the Red Sea does at the present time. Arabia lies between them. The sea on which we are now sailing is 1,200 miles long."
"Badaeker gives the length as 1,400 miles," said Louis.
"He gives it in English miles," replied the commander. "A degree of a great circle is 69.07 English, or statute miles as we call them, or 60 geographical sea miles or knots. This distinction has been fully explained to you before. For ordinary purposes the number of sea miles is to the number of statute miles in the ratio of six to seven. In other words, there will be six-sevenths as many knots as statute miles, and conversely, seven-sixths as many statute as sea miles. Six-sevenths of 1,400 is 1,200; and thus we agree.
"The Red Sea varies in width from 100 to 200 miles, and in the broadest part it is 205 sea miles. We are still in the Gulf of Suez, and shall be till about five this afternoon. On the African side you will see mountains all the way to the strait, with only sand between them and the water. There is nothing that can be called a town between Suez and Koser, over 300 statute miles. All around the sea are coral-reefs; and we shall pass a lighthouse on one right in the middle of it. Not a single river flows into the Red Sea, for there are no rains in Egypt; and if there were on either side, the desert would absorb all the water.
