It struck me that, since nothing was known, an inquiry into the subject--provided an inquiry was possible for a stay-at-home--might help the matter forward to a certain extent. So, as it was well known that the temples in Egypt had been most carefully examined and oriented both by the French in 1798 and by the Prussians in 1844, I determined to see whether it was possible to get any information on the general question from them, as it was extremely likely that such temples as that at Eleusis were more or less connected with Egyptian ideas. I soon found that, although neither the French nor the Germans apparently paid any heed to the possible astronomical ideas of the temple-builders, there was little doubt that astronomical considerations had a great deal to do with the direction towards which these temples faced. In a series of lectures given at the School of Mines in November, 1890, I took the opportunity of pointing out that in this way archæologists and others might ultimately be enabled to arrive at dates in regard to the foundation of temples, and possibly to advance knowledge in several other directions. After my lectures were over, I received a very kind letter from one of my audience, pointing out to me that a friend had informed him that Professor Nissen, in Germany, had published some papers on the orientation of ancient temples. I at once ordered them. Before I received them I went to Egypt to make some inquiries on the spot with reference to certain points which it was necessary to investigate, for the reason that when the orientations were observed and recorded, it was not known what use would be made of them, and certain data required for my special inquiry were wanting. In Cairo also I worried my archæological friends. I was told that the question had not been discussed; that, so far as they knew, the idea was new; and I also gathered a suspicion that they did not think much of it. However, one of them, Brugsch Bey, took much interest in the matter, and was good enough to look up some of the old inscriptions, and one day he told me he had found a very interesting one concerning the foundation of the temple at Edfû. From this inscription it was clear that the idea was not new; it was possibly six thousand years old. Afterwards I went up the river, and made some observations which carried conviction with them and strengthened the idea in my mind that for the orientation not only of Edfû, but of all the larger temples which I examined, there was an astronomical basis. I returned to England at the beginning of March, 1891, and within a few days of landing received Professor Nissen's papers. I have thought it right to give this personal narrative, because, while it indicates the relation of my work to Professor Nissen's, it enables me to make the acknowledgment that the credit of having first made the suggestion belongs, so far as I know, solely to him.[1]