[1] “Baugeschichte des Dendera-Tempels.” 1877.
[2] “Archæologia,” vol. lviii.
CHAPTER II
THE ASTRONOMICAL DIVISIONS OF THE YEAR
It is next important to deal with the yearly path of the sun, with a view of studying the relation of the various points of the horizon occupied by the sun at different times in the year. In the very early observations that were made in Egypt, Chaldæa and elsewhere, when the sun was considered to be a god who every morning got into his boat and floated across space, there was no particular reason for considering the amplitude at which the boat left, or came to, shore. But a few centuries showed that this rising or setting of the sun in widely varying amplitudes at different times of the year at the same place obeyed a very definite law.
In its northward passage it reaches the highest point at our summer solstice, and then goes down again till it reaches its greatest southern declination, as it does in our winter. At both these points the sun appears to stand still in its north or south movement, and the Latin word solstice exactly expresses that idea. The change of declination brought about by these movements will affect the place of the sun’s rising and setting; this is why the sun sets most to the north in summer and most to the south in winter. At the equinoxes the sun has always 0° Decl., so it rises and sets due east and west all over the world. But at the solstices it has its greatest declination of 231⁄2° N. or S.; it will rise and set therefore furthest from the east and west points; how far, will depend upon the latitude of the place, as will have been gathered from the preceding table ([p. 11]).
These solstices and their accompaniments are among the striking things in the natural world. In the winter solstice we have the depth of winter, in the summer solstice we have the height of summer, while at the equinoxes we have but transitional changes; in other words, while the solstices point out for us the conditions of greatest heat and greatest cold, the equinoxes point out for us those two times of the year at which the temperature conditions are very nearly equal, although of course in the one case we are saying good-bye to summer and in the other to winter.
Did the ancients know anything about these solstices and these equinoxes? Dealing with the monumental evidence in Egypt alone, the answer is absolutely overwhelming. Many thousand years ago the Egyptians were perfectly familiar with the solstices, and therefore with the yearly path of the sun.
This fundamental division of the sun’s apparent revolution and course which define our year into four nearly equal parts may be indicated as in [Fig. 5], the highest point reached by the sun in our northern hemisphere being represented at the top.