"The Doctor had a magnifying-glass in his pocket, and we looked at some of the sand with it. It is not composed of angular fragments with sharp corners, such as you will see in the sand which you dig from the ground at home, but every particle is worn as smooth as the marbles that boys play with, or as the 'cobble-stones' with which our streets are paved. Many centuries of attrition under the winds of Africa have done the work.
"Do you want to know how large the Great Pyramid is?
"Well, it is about seven hundred and forty feet square, and four hundred and eighty feet high. It covers an area of nearly thirteen acres, and contains eighty-nine million cubic feet of stone. What do you suppose you could do with that amount of stone?
EGYPTIAN CAPTIVES EMPLOYED AT HARD LABOR.
"You could build a wall four feet high and two feet thick—a good wall for a farm or yard—all the way from New York to Salt Lake City; in round figures, two thousand miles! If you wanted a good solid wall, twelve feet high and four feet thick, from Cincinnati to St. Louis (three hundred and forty miles), you would find the stone for it in this Great Pyramid! And if New York City is in danger of an attack, and wants to surround the whole of Manhattan Island (twenty-one miles around) with a wall forty feet high and twenty feet thick, here is the material to do it with. And remember that all this stone was hewn from the quarries, and moved and set up, centuries before the power of steam was known!
