it the "pyramid inch," he makes the base of the pyramid express the number of miles in the diameter of the earth. Now in the interior of the apparently solid structure, besides the usual slanting passage down to a kind of cellar or vault beneath the middle of the base, which may have been used for a sepulchral resting-place, there are two slanting passages, one running north and the other running south, and slanting up at different angles. Part of that which leads south is much enlarged, and is known as the grand gallery. It is of a very remarkable shape, being perfectly smooth and polished along its ascending base, as indeed it is in every part, and having a number of steps or projections, pointing also upwards at certain angles, very carefully maintained. Whether we understand its use or not, it is very plain that it has been made with a very particular design, and one not easily comprehended. This leads into a chamber known as the king's chamber, whose walls are exquisitely polished and which contains a coffer known as _Cheops' Coffin_. This coffer has been villainously treated by travellers, who have chipped and damaged it, but originally it was very carefully made and polished. It is too large to have been brought in by the only entrance into the chamber after it was finished, and therefore is obviously no coffin at all, as is proved also by the elaborateness of the means of approach. Professor Piazzi Smyth has made the happy suggestion that it represents their standard of length and capacity, and points out the remarkable fact that it contains exactly as much as four quarters of our dry measure. As no one has ever suggested what our "quarters" are quarters of, Professor Smyth very naturally supplies the answer--"of the contents of the pyramid coffer." There are various other measurements that have been made by the same worker, and their meaning suggested in his interesting book, _Our Inheritance in the Great Pyramid_, which we may follow or agree to as we can; but from all that has been said above, it will appear probable that this pyramid was built with a definite design to mark various natural phenomena or artificial measures, which is all we require for our present purpose. Now we come to the question, what is the meaning of the particular angles at which the north-looking and south-looking passages rise, if, as we now believe, they must have _some_ meaning. The exits of these passages were closed, and they could not therefore have been for observation, but they may have been so arranged as to be a memorial of any remarkable phenomena to be seen in those directions. To ascertain if there be any such to which they point, we must throw back the heavens to their position in the days of the Egyptians, because, as we have seen, the precession of the equinoxes alters the meridian altitude of every star. As the passages point north and south, if they refer to any star at all, it must be to their passing the meridian.