THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



SUPPLEMENT to VOL. XXIV. THIRD SERIES. 



LXVII. Observations on the Entrance Passages in the Py- 

 ramids qfGizeh. By Sir John F. W. Herschel, Bart., 

 F.R.S., with Introductory Remarks by Col. Howard Vyse*. 

 yV.S it had been supposed that the inclined passages were in- 

 •*■** tended for astronomical purposes, I mentioned the cir- 

 cumstance to Sir John Herschel, who with the utmost kind- 

 ness examined the annexed table, and entered into various 

 calculations to ascertain the fact. I also informed Sir John 

 of the allusion in the Quarterly Review to M. Caviglia's re- 

 marks respecting the polar star, and likewise of its having 

 been seen by Captains Irby and Mangles from the inclined 

 passage in the Great Pyramid at the period of its culminating, 

 on the night of 21st March 1817. 



M. Caviglia's remarks, contained in a letter to Mr. Hamil- 

 ton, dated September 21st, 1818, are as follow: — 



" Tous les chemins qu'il y a dans l'interieur de ce monu- 

 ment (la Grande Pyramide), ceux qui sont en pente, forment 

 un angle de 27° avec ceux qui sont en ligne horizontale. 

 Mais ce qui a merite mon attention est que Ton cesse de voir 

 Petoile polaire on avanfc qu'on eut bouche le chemin Ton 

 cessoit de descendre pour monter." 



M. Caviglia no doubt could have seen the star from this 

 passage, but the manner in which he observed it is not clearly 

 described, nor can, after all, any conclusion be drawn from the 

 present length of the passage, either from the entrance to the 

 beginning of the ascending communication, or in any other 

 parts of it, because, owing to the dilapidated state of the ex- 

 terior of the pyramid, the top of the passage has lost twenty- 

 one feet six inches of its original length, and of course the 

 bottom proportionably more. 



It would appear that the direction of the passage was de- 

 termined by the star, which was polar at the time when the 

 pyramid was constructed, and that the exact aspect of the 



* Extracted from Col. Vyse's work, entitled " Operations carried on at 

 the Pyramids of Gizeh in 1837," vol. ii. p. 105. 



Phil. Mag. S. 3. No. 162. Suppl. Vol. 2*. 2 I 



