430 
Proceedings of the Royal Society 
Or an approximation to 7 r, as represented by a “ year” of inches 
marvellously close both in the numbers representing the circum- 
ference and diameter, and reproducing here the grander proportions 
of the external form of the pyramid. 
It is to be remembered that the “ year” of inches was divided 
roughly into i and fds, and the three stones of the ceiling and the 
three cuts on the wainscot seem to point to some important divi- 
sion by 3. 
We have seen 7 r playing so important a part in deciding the 
height of the pyramid and the length of the Antechamber, that 
we may at any rate try what a division by 3 will do. 
On the base of the pyramid the “ year ” which represents 
circumference (or, as regards the height of the pyramid 7 r) 
was expressed in units of 100 inches. Have we any chance 
of finding not circumference, for we already have our “year” 
of inches, but diameter, or radius, as a purely mathematical ex- 
pression as regards 7 r, when expressed in say the same terms of 
100 inches ? 
Taking 7 r as represented by 314T59, &c. Pyramid inches, we 
find diameter + radius expressed very closely, as § and | of the 
height of the antechamber ( i.e ., 149*2 // ). 
But when we divide 7 r itself (still expressed in terms of K = 100 
Pyramid inches) by 3, we obtain the figures 104*72, which strike 
us as being an approximation to the height of the wainscot on the 
east wall (103*1); but when we refer to the grand gallery axis (to 
whose connection with the east wainscot our attention has already 
been drawn) we find a still closer approximation (viz., 104 06 P.I.) 
to the expression of-^» 
o 
But is a curious expression, and not much used in calculations 
o 
I am conversant with, except in one instance ; but that instance 
bears on the case, as it is in the calculation of volume of spheres, 
cones, and also pyramids, the area of whose base is expressed in 
terms of 77 -. 
It may be advantageous to note here the connection between the 
volumes of pyramids and spheres. The content of a pyramid is 
mathematically expressed thus, 
