326 H. L. Smith—Queen’s Chamber in the Great Pyramid. 
AO and prolong it to E, making AK equal to 2442 in. Join 
EB and EN’; the angles EBO and EN’O are each equal to 
30° [1].* 
Ton ED ; it will cut N’B in C, and OC will equal 25 inches. 
Join HO; produce it to meet EB in F, and from F drop a per- 
pendicular upon OB; it will meet OB inC; prolong FC, to meet 
HD in B’ it is the axis of the niche. Our equations [11] and [1] 
give results which differ not quite ‘2 in. from 25 inches, but, as 
this number has been adopted by Prof. Smyth, and as a very 
slight variation in our assumed elements would give it exactly, 
we assume OC=25- in. Set off DL equal to 66°68 in., and D 
equal to 127-32 inches, as indicated above ; draw K’'L and SK 
parallel to each other and to HD. Join EL; the triangle EBL 
is isoceles; the angles at the base are each 30°; the same is true 
of the triangle EN’K’ [1v]. The triangle EK’L is equilateral ; 
the angles at E, K’, and L being each 60°, .. EK’ = K’L= EL 
= 205 in. 
Join N’L and BK’ ; they bisect each other in the point M, in 
the line EA; and the angles MN’O, MBO, MK’N, and MLN, 
are each equal to 30° [v]; ... K'B,= LN’,= 2BL,= QN’K', and 
BL,= MB,= BE,= EM,= EN’= N'M,= N’K',=K™M._ With 
M asacenter, and radius = ME, describe the are N’EB; N M 
will represent the polar axis, and E the zenith, at the latitude 
Li : 
_ From the point F’, drop the per endicular F’H” upon HD; 
it will bisect OB in 0”, and pass through the point P, pipe 
K 
great pyramid, and the angles yHD and yDH will eae be 
/ 
Join Ly, and prolong it to meet HN’ produced, in y sn 
Me . f PP ° ! xX}; upper 
y'M; the angle y'MS” will equal 33° 42 nearly [ pole 
been @ 
_ Through J, intersection of K’L, and axis of niche, draw I 
meeting HN’ in 6; join 6M; the angle 3MS” will equal 2 
nearly [xr], direction of lower culmination of @ Draconis. BA 
_ Set off CO’, equal to 12°5 inches join K’O’, intersech™® will 
nV. Joi ,and DV; the angles HVA; and A 
each be equal to 33° 42’ nearly [x1i]. 
*“ The numbers in brackets refer to the equations at 
the end of this article. 
