268 SCIENCE PROGRESS 



Now there are three long passages in the Great Pyramid, of which one 

 points northward and two southward ; the inchnation of these passages is 

 approximately equal, and Piazzi Smyth concludes the angle of inclination 

 originally to have been, in all cases, 



26° 18' Io^ 



However, as Colonel Howard Vyse in his earlier measurements gave 

 26° 41' for the northern passage, it would seem (assuming all three had 

 originally the same inclination) that 



26° 37' r-1 



is not extravagantly wide of the mark. In any case, the accordance is 

 near enough to be striking, and more than near enough to be practicable. 

 For in spite of its length of 109 -(- 156 feet the southward-pointing passage, 

 having a height of 47 inches, permits of a variation of ± 2° 3' in the direc- 

 tion of vision when using the passage as an instrument of astronomical 

 observation. That is to say, altitudes ranging between 



24° 15' 

 and 



28° 21' 



could be taken by using suitable " sights "; and this, too, even if we accept 

 the smaller value of 26° 18' 10" (Piazzi Smyth). 



The last sentence prompts the reflection that the ' mid-winter ' point 

 could likewise be observed ; for the Sun's south declination on December 21st 

 would then be 35° 25' 47", whence altitude = 24" 35' 22*, which is within 

 the range given. 



To summarise briefly : It has been shown that, assuming Drayson's 

 cycle to be a fact in nature : — 



(i) The Great Pyramid is so situated as to have the Sun exactly — exactly — 

 in its zenith at the epochs of 'spring ' and ' autumn ' in the Great Year. 



(ii) A southward-pointing passage, of great length, exists in the Pyramid, 

 and is inclined at such an angle as to render possible a minutely accurate 

 observation of the Sun's altitude, sufficient to determine just when those 

 points in the cycle corresponding in the common year to December 21st 

 (mid-winter) and February 4th (' commencement ' of spring) had been 

 reached. 



(iii) These facts, if not mere coincidences, certainly appear co-related. 

 And i/ they are only coincidences, then, as the reader has been reminded in 

 the first paragraph of this letter, they are not isolated coincidences ; for 

 there is another, independent of them, which also demands explanation. 



It is true that all this implies an antiquity for the Great Pyramid greatly 

 exceeding that usually attributed to it. But does not Herodotus state that 

 the Egyptian priests claimed that their archives recorded astronomical 

 observations extending over more than three cycles of precession ; and 

 are we altogether justified in an a ■priori disbelief in such a claim ? 



One more point may be mentioned. The north-pointing ^-psissage in the 

 Pyramid, as has been stated, is given an inclination of 26° 41' by Colonel 

 Howard Vyse ^ ; and since the point of the heavens thus exposed to view 

 is 3° 18' below the pole, it has been argued with great confidence by various 

 writers on the archaeology of the Pyramid, that it dates from the time 

 when — by the orthodox motion of the pole — the fixed star Alpha Draconis 



^ This value would appear to be accepted if not endorsed by Sir John 

 Herschel, according to the note on p. 771, vol. vii, Encycl. Britt. (ninth 

 edition), article " Egypt." Writing away from books of reference, I cannot 

 look up sources. — ^A. H. B. 



