31G 



KNOWLEDGE 



[Feb. 10, 1882. 



unless they camf t<if> near tho mouth of the (iuWery. Or 

 thpy might l»- ilosi' t<« tlu; nioiitli of Uh- (Jiillrry nt its 

 kidcs, witliout obstriiitinj,' tlu' view. 



liut now, notice tluit if tho ])laco tlioy tliux occupied - 

 thr future King's Clianilicr (periiaps, as Uu; region in or nrar 

 \vhiih all the oliservations of the heavenly host in cuhiiinn- 

 tiiPM had been made) werejn the centre of the S(|uar(! top 

 of the Pyramid as thus fur built, they would Ix- very much 

 in the way of other observers, who ought to be stationed 

 at certain special points on tli;s horizontal top, to oliservo 

 certain important horizontal lines, viz , the lines directed 

 to the cardinal f)oint3 and to points mid way between these. 

 j\i\ observer who had this task assigned In'ni should 

 (H cupy the very centre of the s«|uare top of the, n-s yet, 

 iucomplete Pyramid, so that the middle point of each side 

 would mark a cardinal point, while the angles of the square 

 would mark the mid-cardinal points. Also this central 

 I'oiiit ought not only to command direction lines to the 

 angles and bisections of the sides, but to be counnanded, 

 without obstruction, by direction lines from these points. 



Thus the upper end of the Great Ascending Gallery should 

 not be exactly at the centre, but somewhat either to the 

 west or to the east of the centre of tlie great square sum- 

 mit of the incomplete Pyramid. 



Let us sec how this matter was actually arranged : — 

 Fig. 1 shows the incomplete Pyramid, as supposed to 

 be viewed from above. The four sockets, s.iv., n.w., n.e., 

 and s.e., were supposed, until quite recently, to mark the 

 exact position of the four base angles of the Pyramid. It 

 turns out, however, that they are rather below the level of 

 the real basal plane of the structure, which is, therefore, 

 somewhat smaller than had been suppo.^cd. 



Fig. 1 is, however, cliiefly intended to show the nature 

 of the square platform, w^hich formed the top of tlie pyra- 

 midal frustum when the level of the floor of tlic gallery 

 of the King's Chamber had just been reached. We have 

 a horizontal section of the Pyramid, in fact, taken through 

 the lioor of the King's Chamber and Antechamber — that is, 

 through SD, in the figure at p. 266. The bottle-shaped 

 black space, near 0, giv(!s the section of the slanting gallery, 

 beginning on the southern side at its widest part, reaching 

 a narrower part somewhat to the north of 0, and theie- 

 aftcr narrowing tow^ards the north, till the section of the 

 uppermost or narrowest part is reached. The dotted lines 

 show where the Grand Gallery and the narrow ascending 

 passage (ascending for one passing towards the King's 

 Chamber) pass downwards into the structure of the Pyra- 

 mid : at e is the place where descending and ascending 

 passages meet. The position, also, of the entrance-hole, 

 forced in by Al Afamoun, at about tlie level of the angle e, 

 is indicated. 



At is the centre of the square surface, which then 

 formed the top of the structure. If posts were placed at the 

 angles ')i.u:, a.u:, s.e., s.tc, and also at n., e.., »., and »',, an 

 obierver stationed at would have the cardinal and the 

 mid-cardinal points e.xactly indicated. Now the point is 

 about eight and a-half paces from the middle of the southern 

 opening of the Grand tJallery ; so that, if there were an 

 assistant observer at n, he could communicate time 

 signals readily both to the observers in the (Jallery and to 

 the observer at 0. All such observations as thci easting, 

 southing, westing, and northing of heavenly bodies would 

 belong to the observer at 0, uprights of suitable height 

 Vicing erected at n., c, s., and v. He could also observe 

 when heaveidy bodies passed the mid-cardinal directions, 

 n.ir.j s.u\, s.e., and s.ir. It will be noticed that if we 

 .suppose the Grand (Jalleiy completed, which would carry it 

 to a height of about 28 ft. above the level of tlio floor at o, 

 the slant of the (iallcry would yet be such that the observer 



at O, Kupj)osing him to observe by njcans of an instrum" i. 

 raiKetl a few feet altove the level of the floor, would !•• 

 perfectly well able to look along the horizontal dire( ti<.i 

 line from to s.n: (Most of his observations would, < 

 course, Ixr direct*;d to jioints above the horizon.) 



IJut I think if I were planning such observations on tb' 

 squan? suiface e., n., ir., v., I sliould wish to have sever.i 

 observers at work in thus tiking azimutlis (directioi 

 refen-ed to the cardinal points) and altitudes, just as severe 

 transit observers were manifestly provided for in the coi 

 struction of tlie (!rand '^■allerv. 



Fig. 2. — Vertical Section of Grand Gallery. 



1 should set an observer at n., to observe in dire^tioii 

 ii.-n.ii\, )(,-((•., U.S. (that is, n.O.), n.-e., and u-s.u: ; anotlu ; 

 at ('•., another at '., and another at c, to oliserve in tli 

 corresponding directions belonging to their stations. Ob- 

 servers at n.ir, .«.;'•., s.f., and s.ir. could also do excellent 

 woik. In fact, they, between them, could take the hori- 

 zontal cardinal and mid-cardinal directions better than the 

 oViserver stationed at 0, though his would be the best 

 station for general work with the astrolabe. 



Yet again, for observing heavenly bodies at considerable 

 altitudes, stations nearer to the uprights at s.v:, w., luv:. 



