s with the
dates given by those who are considered the best authorities in Biblical
matters,--but so much the worse for the dates.

To return to the pyramid.

We have considered how, probably, the architect would plan the
prolongation of the entrance passage to its place of opening out on the
northern face. But as the pyramid rose layer by layer above its
basement, there must be ascending passages of some sort towards the
south, the most important part of the sky in astronomical research.

The astronomers who planned the pyramid would specially require four
things. First, they must have the ascending passage in the absolutely
true meridian plan; secondly, they would require to have in view, along
a passage as narrow as the entrance tunnel, some conspicuous star, if
possible a star so bright as to be visible by day (along such a tunnel)
as well as by night; thirdly, they must have the means of observing the
sun at solar noon on every day in the year; and fourthly, they must also
have the entire range of the zodiac or planetary highway brought into
view along their chief meridional opening.

The first of these points is at once the most important and the most
difficult. It is so important, indeed, that we may hope for significant
evidence from the consideration of the methods which would suggest
themselves as available.

Consider:--The square base has been duly oriented. Therefore, if each
square layer is placed properly, the continually diminishing square
platform will remain always oriented. But if any error is made in this
work the exactness of the orientation will gradually be lost. And this
part of the work cannot be tested by astronomical observations as exact
as those by which the base was laid, unless the vertical boring by which
the middle of the base, or a point near it, was brought into connection
with the entrance passage, is continued upwards through the successive
layers of the pyramidal structure. As the rock rises to a considerable
height within the interior of the pyramid,[44] probably to quite the
height of the opening of the entrance passage on the northern slope, it
would only be found necessary to carry up this vertical boring on the
building itself after this level had been reached. But in any case this
would be but an unsatisfactory way of obtaining the meridian plane when
once the boring had reached a higher level than the opening of the
entrance passage; for only horizontal lines from the bor