There is a great desert in the interior of North America. It is almost as large as the famous Saara of Africa. It is fifteen hundred miles long, and a thousand wide. Now, if it were of a regular shape-that is to say, a parallelogram-you could at once compute its area, by multiplying the length upon the breadth; and you would obtain one million and a half for the result-one million and a half of square miles. But its outlines are as yet very imperfectly known; and although it is fully fifteen hundred miles long, and in some places a thousand in breadth, its surface-extent is probably not over one million of square miles, or twenty-five times the size of England. Fancy a desert twenty-five times as big as all England Do you not think that it has received a most appropriate name when it is called the Great American Desert?"