42 



NATURE 



[May II, 189^ 



bluejackets, which Captain Lang had taken the precaution to 

 place in the immediate neighbourhood of the instruments ; indeed 

 both here and at Bathurst the natives were sufficiently well 

 informed to watch the progress of the eclipse through smoked 

 glass. The cause of the eclipse seems to have been ascribed to 

 the Almighty, and not in any way associated with the presence of 

 the astronomers. The members of the expedition themselves 

 had no opportunity of studying the effect of the eclipse upon the 

 brute creation, but trustworthy observers in Bathurst report 

 that the usual state of alarm prevailed amongst fowls, cats, and 

 other animals. Immediately after the eclipse the huts were 

 partly dismantled, and the observers and their instruments were 

 photographed by Prof. Thorpe, exactly as during the operations, 

 the astonished natives meanwhile gathering in large numbers. 

 After a short rest, the work of dismounting and packing the 

 instruments was begun, and before sunset considerable progress 

 had been made. By the evening of April 17, all was packed and 

 safely aboard the Alecto, and the only material remnants of the 

 expedition were waste paper and a slab of cement, prepared 

 and inscribed by Lieutenant Hills, with the words, " British 

 Eclipse Expedition, April i6, 1893." It is impossible to speak 

 too highly of the assistance rendered to the expedition by the 

 officers and men of the ^/ivr/c. As already stated, Lieutenant- 

 Commander Lang made independent observations, with the 

 assistance of Lieutenant Colbeck. Prof. Thorpe and Mr. Gray 

 were assisted by Mr. Pym, and myself by Lieutenant Shipton 

 and Chief Artificer Milligan, Lieutenant Hills by Dr. Moore, 

 Sergeant Kearney by Sergeant Williams, and Mr. Collick and 

 Mr. Forbes, by Mr. Willoughby, the engineer, and Mr. Murphy, 

 one of the artificers. 



The expedition left Fundium on April 18, and arrived at 

 Bathurst on April 19, where H.M. S. Blonde was waiting 

 under orders to convey the party to Grand Canary. With- 

 out this convenient arrangement, the expedition could not 

 have left Bathurst before ISIay 3 or 4. The homeward journey 

 to England will be completed by a passage in the first available 

 steamer. 



THE ORIENTA TION OF GREEK TEMPLES} 



'T'HIS investigation is supplementary to Mr. Lockyer's exam- 

 ination of the orientation of the Egyptian temples, in the 

 course of which he has cited passages translated from hierogly- 

 phics, showing most distinctly that there was a connection 

 between the foundation of those temples and certain stars. He 

 hasalso shown that the structure of the temples demonstrates that 

 the light from these stars must have been admitted at their rising 

 or setting along the axis of the temples through the doorways, 

 and that in certain temples the doorways have been altered 

 in such a way as to follow the amplitude of the star as it 

 changed, owing to the precession of the Equinoxes, and that in 

 some cases a new temple had been founded alongside of an older 

 one for the same purpose. 



Although there does not seem to be any historical or epi- 

 graphical record of such a nature in Greece, the architectural 

 evidence is not wanting. On the Acropolis of Athens there are 

 two temples, both dedicated to Minerva, lying within a few 

 yards of one another, both apparently oriented to the Pleiades, 

 the older temple to an earlier position of the star group, and 

 the other to a later one. At Rhamnus there are two temples 

 almost touching one another, both following (and with accordant 

 dates) the shifting places of Spica. In a temple at ^Kgina a 

 doorway placed excentrically in the west wall of the cella was 

 adapted for the observation of a setting star. 



A clue is given for finding out the dates of the foundations of 

 temples oriented to stars by means of the changes produced upon 

 them by the precession of the Equinoxes ; a movement which 

 induces a divergence between the latitudes and longitudes of 

 stars, and their places reckoned in declination and right ascen- 

 sion ; so that after the lapse of 200 or 300 years a star which 

 rose or set in the direction of the axis of a temple would have 



J Abstract of a paper (read before the Royal Society on April 27), ** On the 

 Results of an Examination of the Orientation of a number of Greek Temples, 

 with a view to connect these Angles with the Amplitudes of certain Stars at 

 the time these Temples were founded, and an endeavour to derive therefrom 

 the Dates of their Foundation by consideration of the changes produced upon 

 the Right Ascension and Declination of the Stars arising from the Preces- 

 sion of the Equinoxes." By F. C. Penrose, F.R.A.S. Communicated by 

 Prof. J. Norman Lockyer, F.R.S. 



passed to a different amplitude, so as to be no more available 

 for observation, as before, from the adytum. 



In the earlier ages of Greek civilisation the only accurate 

 measure of time by night was obtained by the rising or setting 

 of stars, and these were more particularly observed when helia- 

 cal, or as nearly as possible to sunrise. For the purpose of 

 temple worship, which was carried on almost exclusively at sun- 

 rise, the priests would naturally be very much dependent for 

 their preparations on the heliacal stars as lime warners. 



The orientation of temples may be divided into two classes, 

 solar and stellar. In the former the orientation lies within the 

 solstitial limits ; in the latter it exceeds them. In Greece there 

 are comparatively few of the latter class. 



In the lists of temples which follow, all the orientations were 

 obtained from azimuths taken wilh a theodolite, either from the 

 Sun or from the planet Venus. In almost every case two or 

 more sights were observed, and occasionally also the perform- 

 ance of the instrument was tested by stars at night. The heights 

 subtended by the visible horizon opposite to the axes of the 

 temples were also observed. 



The first list comprises twenty-seven intra-solstitial temples: 



7 examples from Athens. i example from Sunium. 



3 ,, Olympia. I ,, Corinth. 



2 ,, Epidaurus. I ,, Bassse. 



2 ,, Rhamnus. i ,, Ephesus. 



2 ,, .(Egina. i ,, Plataea. 



I ,, Tegea. i ,, Lycoaura. 



1 ,, Nemea. i ,, Megalopolis. 



I ,, Corfu. I ,, Argos. 



For all these the resulting solar and stellar elements are 

 given, wilh the approximate dates of foundation, similarly to the 

 following specimen, namely, that of the Temple of Jupitet at 

 Olympia. 



Olympia, lat. 37° 38' N. 



Temple 



of 

 Jupiter 



Orientation 

 angle 



262 57 46 



Amplitude, star or sun 

 Corresponding altitude 



Declination 



Hour angles 



Depression of sun .»... 



Right ascension 



Approximate date 



Stellar 

 elements. 



Solar 



elements. 



8 38 o N. 7 22 14 N. 



3 o o E. 

 -1-8 40 o 

 6hii'"37S 



23" 40"' 



I 43 o E. 

 -1-6 52 22 



14' 12' o" 

 ,h 3". 5S 

 Apr. 6. 



Name 

 of 

 star. 



NO. 1228, VOL. 48] 



This example has been selected from the rest of the list 

 because this temple has been chosen for the purpose of showing 

 the method of procedure in working out the elements from the 

 observations, those, namely, of the orientation angle, and of the 

 height of the visible horizon. 



A few general remarks, however, seem required respecting the | 

 Sun's and star's altitude, and the Sun's depression when the ' 

 star is to be observed. 



For a star to be seen heliacally, it is necessary that the Sun 

 should be just sufficiently below the horizon for the star to be 

 recognised. According to Biot, Ptolemy, speaking of Egypt, 

 has recorded this to be about n°. But where, as generally in 

 Greece, there are mountains screening the glow which at such 

 times skirts the true horizon, it seems fair at any rate for a first 

 magnitude star to consider 10° as sufficient. I have myselfseen 

 Rigel in the same direction as the Sun when elevated 2° 40 

 above the sea horizon, the Sun being less than 10° below. 

 Obviously an observer looking from a dark chamber in a well 

 known direction would be more favourably situated. 



It is proper to allow about 3° of altitude for a star to be seen 

 above low clouds and the hazy glow which skirts the horizon. 

 The Sun's light, however,, seems to be very effective at a lower 

 altitude, and when he appears over a mountain of 2" or 3 

 altitude the angle may properly be reduced by 20' or 25', partly 

 for refraction, and partly because a small segment only of the disc 

 is sufficient for illumination. 



The method I have pursued in working out the example of the 

 Temple of Jupiter at Olympia is as follows. 



The orientation angle, measured from the south point round 

 by way of west and north, is 262^ 37' 46", which is equivalent 

 to an amplitude of ■\- 7^22' 14". The eastern mountain subtends- 

 an angle of 2° 4'. For reasons above given, the solar altitude 



