From this it will be seen that the area of the Great Pyramid (more than 13 acres) is more than twice the extent of that of St. Peter's at Rome, or of any other building in the world. Its height is equal to the highest spire of any cathedral in Europe; for, though it has been attempted to erect higher buildings, in no instance has this yet been successfully achieved. Even the third pyramid covers more ground than any Gothic cathedral, and the mass of materials it contains far surpasses that of any erection we possess in Europe.
All the pyramids (with one exception) face exactly north, and have their entrance on that side—a circumstance the more remarkable, as the later builders of Thebes appear to have had no notion of orientation, but to have placed their buildings and tombs so as to avoid regularity, and facing in every conceivable direction. Instead of the entrances to the pyramids being level, they all slope downwards—generally at angles of about 26° to the horizon—a circumstance which has led to an infinity of speculation, as to whether they were not observatories, and meant for the observation of the pole-star, etc.[1] All these theories, however, have failed, for a variety of reasons it is needless now to discuss; but among others it may be mentioned that the angles are not the same in any two pyramids, though erected within a few years of one another, and in the twenty Avhich were measured by Colonel Vyse they vary from 22° 35' to 34° 5'. The angle of the inclination of the side of the pyramid to the horizon is more constant, varying only from 51° 10' to 52° 32', and in the Gizeh pyramids it would appear that the angle of the passage was intended to have been about one-half of this.
One plausible theory seems to be, that the faces of the pyramid were intended to be practically four equilateral triangles, laid against one another, and meeting at the apex. For instance, in the three great pyramids at Gizeh, the ratios of the sloping edges to the base are as follows:—
| Base. | Length of sloping edge. | Difference. | |
| Great Pyramid | 760 feet | 723 feet | 37 feet. |
| Second Pyramid | 707 " | 672 " | 35 " |
| Third Pyramid | 354 " | 330 " | 24 " |
It will be observed that the difference is least—about 5 per cent—in the second pyramid, the one which retains the greatest part of its
- ↑ They are situated in latitude 30° N.
Vyse, which are by far the most complete and correct which have yet been publislied. It is necessary, however, to warn the reader that Mr. Perring published two sets of measurements, those from actual observation, which are those followed in the text, and another set corrected according to his theory of what they ought to have been, supposing every part to have been set out of an even number of Egyptian cubits. In most instances his theory agrees pretty closely with his observations, but is generally more likely to mislead than guide the reader.
