210 Dr. Arnott on tfie Proportions of the Pyramids of Egypt. 



750 English, its proportion to the height as given by these individuals 

 will be in round numbers: — * 



Base. Height 



Diodorus, 750 643 



Le Bruyn, 750 656 



Prosper Alpinus, 750 625 



Sum, 2250 1924 



Average, 750 641 



and this proportion is nearly as 6 to 5 T \y, or in round numbers as 6 to 5, 

 instead of 3 to 2, or 6 to 4, as in what are deemed the more correct 

 observations. 



But if, instead of the perpendicular height, we suppose these dimen- 

 sions to refer to the slanting height from the middle of one of the sides 

 of the base to the top, and this was the only way in which a measuring 

 line or rod could be actually applied, and the height most easily ascer- 

 tained, we shall find that the above average slanting height will corre- 

 spond to an average perpendicular height of 520 feet,f which, although 

 still too great, is much nearer the truth. 



That Diodorus gave the slanting height from the base to a supposed 

 sharp apex, I have little doubt ; there is more difficulty about the two 

 others mentioned above, as they may have deduced the height by a 

 method similar to Thevenot's; if so, their measurements ought to be 

 entirely rejected: but their introduction does not much disturb the pro- 

 portions given by Diodorus. 



Among the more modern observers, Thevenot makes the base 682 

 French feet, which may possibly be not much under the truth, and the 

 height 520; but this latter was obtained by counting the number of 

 steps, measuring the thickness of a few of them, and thence averaging 

 the whole at 2J feet, French measure; the result would appear 

 to be too great by almost a tenth part. Indeed, the average thickness 

 of all the steps does not seem to exceed 27 or 28 inches English, or 

 scarcely 27 French inches. All attempts, however, at ascertaining the 

 exact height in this way, must yield erroneous and very contradictory 

 conclusions, and unless confirmed by some other method, may be 

 disregarded. In the Encyclopaedia Britannica, seventh edition, article 

 Pyramid, it is said " the breadth of each step is equal to its height,'' but 

 this is absurd. 



* Ilaving no other works at hand, I have deduced the proportions adopted by me from 

 the dimensions given in the article Eyyi>t alluded to in the above note, and in the article 

 Pyramid of the fifth edition of the same Encyclopaedia, and which are chiefly copied from 

 M. Savary. In the two latter works, the actual measures are distinctly stated to be in 

 French feet, and hence require to be augmented by almost a fifteenth part to convert 

 them into English feet. 



t Were the 641 to indicate the slanting height only up to the present platform, the 

 height of the platform would be 531, which is much too great. 



