248 



NA TURE 



[January i6, 1902 



THE FARMERS' YEARS. 

 I. 



SOME years ago in the "Dawn of Astronomy" I 

 showed how carefully the sun had been observed by 

 the ancient Efjyptians, not only when it rose or set at 

 points most to the north or south, as at the solstices, but 

 also when it rose exactly half-way between these points, 

 that is, east and west at the equinoxes. 



This fundamental division of the sun's apparent re- 

 volution and course which define our year into four 



■Winter solstice. 

 Fig. I. 



nearly equal parts may be indicated as in Fig. i, the 

 highest point reached by the sun in our northern hemi- 

 sphere being represented at the top. 



In order better to consider the problem as it was pre- 

 sented to the early astronomers who built observatories 

 (temples) to mark these points, we may deal with the 

 bearings of the points occupied by the sun on the 

 horizon (either at rising or setting) at the times indicated. 



Equi- 



Winter solstice 



:arings of the sun risings and settings in a plac 

 a N. latitude of 51*. 



These points are conveniently defined by their "ampli- 

 tude " or their distance in degrees from the E. or \V. 

 points of the horizon. In the diagram (Fig. 2) I repre- 

 sent the conditions of our chief British sun-temple, 

 Stonehenge, in latitude 51° N. approximately. 



Taking the astronomical facts regarding the solstices 

 and equinoxes for the first year (1901) of the present 

 century, we find ; — 



Sun enters Aries, Spring equinox, March 21. 



,, ,, (Jeinini, .Summer solstice, June 21. 

 ,, ,, Libra, Autumn equinox, .September 23. 



,, ,, Sagittarius, Winter solstice, December 2 J. 



These points, then, are approximately ninety-one days 

 apart (91 x 4 = 364). 



In Fig. 2 I deal with the "amplitudes" at -Stonehenge, 

 that is, the angular distance along the horizon from the 

 E. and \V. points, at which the sunrise and sunset at the 

 solstices are seen, the equinoxes being seen at the E. and 

 W. points themselves. But as these amplitudes vary 

 with the latitude and therefore depend upon the place of 

 observation, a more general treatment is possible if we 

 deal with the declination of the sun itself, that is, its 

 angular distance from the equator. 



The maximum declination depends upon the obliquity 

 of the ecliptic, that is, the angle between the plane of the 

 ecliptic and that of the equator at the time of observa- 

 tion. When the .Stonehenge Sarsen Stones were erected 

 this angle was 23 54' 30". Its mean value for the 

 present year is 23' 27' 7 ; it is decreasing very slowly. 



It will be obvious from Fig. 2 that in temples built to 

 observe the solstices or equinoxes, if they were open 

 at both ends, looking in one direction we should see the 

 sun rising at a solstice or equinox, and looking in the 

 other we should see the sun setting at the opposite 

 one. This, however, interfered with the ceremonial, 

 which required that the light should illuminate a naos 

 generally dark, so, usually, two temples were built back 

 to back, with a common axis, as at Karnak. 



In the beginning of astronomical observation it was 

 more easy to align accurately a solstitial temple than an 

 equinoctial one. 



So much, then, for the chief points in what we may 

 term the astronomical year, those at which the sun's 

 declination is greatest and least. We see that they are 

 approximately ninety-one days apart — say three months. 

 Now the priest-astronomers in these temples could 

 only have won and kept the respect of the agricultural 

 population with which alone they were surrounded in 

 early times, and by whom they were supported, by being 

 useful to them in some way or another. This could only 

 have been in connection with what we may term generally 

 the ftoini/iL,' operations necessary at different times of 

 the year, whether in the shape of preparing the ground 

 or gathering the produce. 



A very large part of mythology has sprung out of the 

 temple cults, prayer, sacrifice and thanksgiving con- 

 nected with these farming operations, in different lands 

 and ages, but it is not my purpose to touch upon this 

 side of the question now at length. 



I wish to show, however, that by studying the orienta- 

 tion of ancient temples erected to watch the sunrise and 

 sunset at times other than the solstices or equinoxes an 

 immense amount of information may be gained if we 

 endeavour to find the way in which the problem must 

 have been attacked before the year was thoroughly 

 established, and when it was still a question of grass- or 

 corn-kings or gods who had to be propitiated. 



In a solstitial temple the sun only makes its appearance 

 once a year, when it reaches its greatest "north or south" 

 declination : but in the temples dealing with lower declina- 

 tions the sun appears twice, once on its journey from the 

 summer to the winter solstice, and again on its return. 



The first difficulty of the inquiry in the direction I 

 have indicated arises from the fact that the products of 

 different countries vary, and that identical farming opera- 

 tions have to be carried on at diflerent times in these 

 countries. We must, then, begin with some one country, 

 and as the record is fullest for (ireece I will begin 

 with it. 



The first thing we find is that the chief points in the 

 farmer's year in Greece are about as far from the fixed 

 points in the astronomical year as they well can be. 



NO. 1 68 I, VOL. 65] 



