EGYPTIAN SCIENCE 



withstanding the size of this host of workers, the task 

 occupied twenty years. We must not place too much 

 dependence upon such figures as these, for the ancient 

 historians are notoriously given to exaggeration in 

 recording numbers ; yet we need not doubt that the re- 

 port given by Diodorus is substantially accurate in its 

 main outlines as to the method through which the 

 pyramids were constructed. A host of men putting 

 their added weight and strength to the task, with the 

 aid of ropes, pulleys, rollers, and levers, and utilizing 

 the principle of the inclined plane, could undoubtedly 

 move and elevate and place in position the largest 

 blocks that enter into the pyramids or what seems 

 even more wonderful the most gigantic obelisks, 

 without the aid of any other kind of mechanism or of 

 any more occult power. The same hands could, as 

 Diodorus suggests, remove all trace of the debris of 

 construction and leave the pyramids and obelisks 

 standing in weird isolation, as if sprung into being 

 through a miracle. 



ASTRONOMICAL SCIENCE^ 



It has been necessary to bear in mind these phases 

 of practical civilization because much that we know 

 of the purely scientific attainments of the Egyptians 

 is based upon modern observation of their pyramids 

 and temples. It was early observed, for example, 

 that the pyramids are obviously oriented as regards 

 the direction in which they face, in strict accordance 

 with some astronomical principle. Early in the nine- 

 teenth century the Frenchman Biot made interesting 

 studies in regard to this subject, and a hundred years 



VOL. I 3 33 



