678 PROF. C. p. SMYTH ON THE REPUTED METROLOGICAL SYSTEM 



First, we may remark, of the chambers, — the top of the topmost chamber of 

 construction is on the level of the upper side of the square EF. The floor of the 

 so-called " King's chamber," is nearly on a level with the line LN, or ^ the semi- 

 diameter below EF. The floor of the " Queen's chamber," so called, is nearly on 

 a level with the line OP, or | the semi-diameter below EF ; and the floor of the 

 subterranean chamber is on a level with the line C'S, or i below the centre ; and 

 these are all the chambers known to exist in the Pyramid. 



Second, of the passages, principal. The entrance passage places itself exactly 

 on our hypothetical line C'*', until very near its lower termination. The ascend- 

 ing passage, with the floor of the grand gallery, also place themselves exactly on 

 our hypothetical line, in fig. 3, QRL ; and the horizontal passage places itself also 

 on our line, RO. 



Now, the angular direction of C'*', (QRL being the same angle inverted), is made 

 by construction the same as that of C* ; and that again depends on the height 

 of the Pyramid as radius, and the semi-side of the square of area as sine ; and 

 =26° 18' 10". This might be looked on at first as a pure geometrical result, but 

 it depends on the measured height and base of the actual Pyramid; and, further, 

 it agrees unexpectedly with the measured angle of the entrance passage, which 

 has hitherto been universally allowed an astronomical signification ; viz. to point 

 to « Draconis, the Pole star of 2121 e.g., at its lower culmination, or, according 

 to Sir John Herschel, 26° 15' 45" ; and inasmuch as the best measures of the 

 actual angle of the Pyramid passages are anywhere between 25° 55' and 27°, 

 our hypothesis is as fair as it need be. 



That hypothesis next gives the line CE, as at an angle of 45°, of course ; but 

 it is further, and architecturally testified to in the Pyramid, according to Col. 

 Howard Vyse's plate, by the line of the Southern air-channel being also at an 

 angle of 45° ; or one of the geodetic indications we are seeking. 



The Northern air-channel on the contrary, his plate makes at an angle of 33° 

 or 34°, for the drawing is not fully accurate ; let us say, then, 33° 42'. If, then, 

 the mean of this and the angle of the entrance passage, the only remaining com- 

 munication from the Pyramid's interior to the outer air, on the same northern 

 side be taken, it is equal to 30° ; or the same as our hypothetical line C 30°', 

 which is by construction = to C 30°, and which depends on the semi-diameter of 

 the area-square as sine, and the radius of a circle of equal area to the base of the 

 Pyramid, as radius ; and is the other geodetic indication being sought. 



Strictly computed, with the 116'5 and 183 metrons to start from, this theoretical 



Goedetic or Latitude angle is 



29° 59' 59-2", 



and reminds us that the observed Latitude of the Pyramid in 1799, was less than 

 80°, and more than 29° 59'. 



On the one hand, however, it may be said, that, given a Pyramid built to realise 



