Really? It seems that figures 3 and four also exist on that page.
These oscillations, in a magnified form, are shown in Figure 4. They point to an inter-action of the earlier precessional forces, affecting the earth's axis in its former nearly upright position [see
], with those later predominating ones associated with its new and greater inclination. The curve of oscillations may thus be regarded as the resultant of these forces, the latter tending to retard, and the former to hurry the precession. The curve, which is a harmonic sine curve, with diminishing amplitudes, is in harmony with the consequences of the disturbance of a spinning body. The oscillations are accounted for by the inertia of the rotating body, alternately retarding and hurrying the precession (
). The rule is stated thus:
i. Hurry the precession, the top rises. (
5)
ii. Retard the precession, the top falls."
....
The relationship of the horizontal and vertical co-ordinates is then such that, if pairs of lines, horizontal and vertical, are drawn on the graph from points indicated by the table above, each pair will meet exactly on the observational curve.
Thus, they all agree completely in showing that the curve which fits the ancient, mediaeval, and recent observations between 2345 B.C., and 1850 A.D., is none other than an exact logarithmic sine curve.
This type of curve is illustrated in J. Edwards'
Differential Calculus 1896, p. 102. It is a curve of recovery, with restoration to equilibrium after a disturbance; and it shows with certainty that a disturbance of the earth's axis occurred at the date 2345 B.C., corresponding to the 0º end of the curve; and that its restoration to equilibrium was completed by the year 1850 A.D., corresponding to the 90º end of the curve.
The exact coincidence of the mean curve of the observations with a logarithmic sine curve, combined with the simple scale relationship just pointed out, enables us to obtain a numerical formula for this curve of the residuals.
The formula is:
d1 ε = 75 x (10.0000000 log sin (T1 x 2.14592 º) (see note)
where d1 ε = the difference between Newcombs Formula and any point on
the Mean Curve of observations, and
T1 = the number of centuries after 2345 B.C.
This formula enables us to calculate the Mean Curve value for any date between 2345 B.C., and 1850 A.D."
In Figure 3 the top horizontal line shows the scale of dates from 3000 B.C. to 2000 A.D. On the extreme left, in the vertical column, degrees and minutes of the vertical scale are shown, reading vertically downwards from 0º to 2º 35'. The residuals, (i.e., differences between Newcomb's Formula and the observed values), are plotted with reference to these two scales, and the mean curve connecting them is drawn, as shown in the Figure. It will be seen by inspection that when the curve is produced downwards, it tends to become vertical about the date 2345 B.C. Continuing the curve upwards, it becomes completely horizontal about the date 1850 A.D. This curve is a logarithmic one. It corresponds exactly to a curve of logarithmic sines." The reader who is well acquainted with mathematical curves can at once recognize this by inspection.
It may also be shown in a graphical way (see Fig. 3). To do this we write beneath the date scale of B.C. and A.D. centuries, in the top horizontal line, a scale of degrees from 0º to 90º. The beginning of this degree scale, 0, is at 2345 B.C., where the curve is vertical; and the end of the degree scale, 90º, is at 1850 A.D., where the curve is completely horizontal. The full period covered by the curve is thus 4194 years, and each degree of the scale corresponds to 46.6 years."
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So, it seems like the curve is based on stuff. Each degree of the curve corresponds to 46,6 years, so I see no reason why the curve would not be as it is, and head to meet the other data points? If it fits with the other Karnak data point, along the way, great.