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THE POPULAR SCIENCE MONTHLY 



was 3° 34' distant from it; that is, in B.C. 3430 or B.C. 2140. The pas- 

 sage, then, chronicles the time when the pyramid was built — with a 

 seeming choice of alternatives. But the nearer of these is negatived by 

 what we know of Egyptian history and we are thus left with the other, 

 that of B.C. 3430, as the date of the pyramid's construction. The pyra- 

 mid thus dates itself astronomically, which is the first remarkable thing 

 about it. 



It is to be noticed that astronomy here furnishes Egyptology with a 

 fixed epoch from which to go forward or back. We are not here deal- 

 ing with conjectures as to when a certain king or dynasty can be made 



OtOMttRltAL MVrorifEStS APPLICD TO COL. HOWARD vrsi'fc MERIDIAN SECTIOMAL EUVATIQN Of CREAT pmAMIO. 



Geometeical Hypothesis applied to Colonel Howard Vyse's Meridian 

 Sectional Elevation of the Great Pyramid. 



to fit into a general chronologic scheme by the relics it has left us of 

 itself. Calculations from known astronomic data can tell to an exact- 

 ness gauged only by the size of the opening of the passage as seen from 

 below precisely when the pyramid was built with only the choice above 

 described. To deny which would but argue a lack of appreciation of 

 physical science. For that such a pointing can be but the sport of 

 chance, the whole structure of the pyramid emphatically denies. 



The Great Pyramid was in fact a great observatory ; the most superb 

 one ever erected. The building is the most mammoth in the world, 

 and it had for telescopes something whose size has not yet been ex- 

 ceeded. This something which did those old astronomers for instru- 

 ment was the Grand Gallery. As its name implies this was a stone 

 gallery of imposing proportions set on an incline of 26° 17' in the very 

 heart of the structure and pointing south. It is approached by the 



