OF THE GREAT PYRAMID. ^ 669 



accurately the angle, at the Pyramid, represented by the angle ABC, in our 

 fig.L 



Now, early travellers, it seems, though attempting many other measures, 

 seldom ventured upon angles ; or when they did, mentioned this particular angle 

 of the Pyramid, as being almost anywhere between 30° and 60° ; and even Dr 

 Perry in 1 743, who was dissatisfied with all previous measures, and found fault 

 with the regularity of the Pyramid also, stating that the angles of every side were 

 different, and ran thus 40°, 37 5, 35°, and 42°-5, — was wofuUy far from the 

 truth with every one of them. 



Hence there is no angle observation on record worth any attention, until that 

 of the French savans in the celebrated Napoleonic expedition of 1799 ; and they, 

 confining their attention chiefly to the Northern face of the Pyramid, or that upon 

 which the one and only entrance into the Pyramid is found, and looking as well 

 as they could along the broken line of the steps of stones as left by the ravages 

 of the Caliphs, made the angle, — 



51° 19' 4" 



This was in truth an exceedingly close approach, compared to anything that 

 had been previously accomplished ; and it was confirmed by Mr Hamilton, who 

 visited the Pyramid immediately after they had left, or in 1801, and recorded 

 the angle as 



51° 23' 46" 



And though M. Caviglia said the angle, in 1817, was so much as 58°, it is plain 

 that he made no attempt at refinement in his measures. 



In this state, therefore, the matter remained, until Colonel Howard Vyse's all- 

 important discovery in 1^39, of two of the original casing stones, well preserved 

 under the hill of rubbish below the entrance into the Pyramid ; and he found 

 them still firmly in situ ; that is, cemented securely to the grand and admirabl}^ 

 smoothed as well as levelled plateau of rock on which the whole pyramid stands. 



Colonel Vyse's three volumes should be carefully read, and some fifty other 

 authors, to establish the extraordinary importance of this discovery. 



The stones were very large and of the most exquisitely truthful workman- 

 ship : one of them appearing thus in cross section (see fig. 2, on next page). 



The angle of the sloping side, being carefully measured by Mr Brettel, C.E., 

 for Colonel Vyse, came out 5 1° 50' ; but on computing the angle from the linear 

 sides as given above, in Mr Perring's measures, it appears to be = 51° 52' 30-3". 



There is little doubt of the truth really lying between the two results, for 

 I neither of them is to be implicitly trusted ; not the angle observed, because it is 

 |. exceedingly improbable that the clinometer employed was equal to the unusually 

 high precision required in this case ; and not the angle computed from the sides, 

 because those sides were not only measured with a rudeness, of merely to " the 



