320 



NA TURE 



[August 3, 1893 



and Denderah a Ursae Majoris was used before it 

 became circumpolar. We deal with 5000 B.C. 



Since undoulDtedly new temples with nearly similar 

 amplitudes (such as that denoted by M at Karnak) were 

 built in late times, we find so long a range of time indi- 

 cated that the utility of the stellar observations from the 

 yearly point of view could scarcely have been in question. 



It may be suggested therefore that the observations 

 made in them had to do with the determination of the 

 hours of the night ; this seems probable, for in Nubia at 

 the present day time at night is thus determined. 



It may be that such stars as Canopus were used by the 

 southern peoples for the same purpose as o Ursse Majoris 

 first and then y Draconis were used by the northerners. 

 In other words, the question arises whether the extreme 

 north and south stars were not both used as warners of 

 the dawn all the year round. 



It is well known that in quite early times means had 

 been found of dividing the day and night into 12 hours. 

 In the day shadows cast by the sun, or sundials, might 

 have been used, but how about the night .' 



We have seen that the Egyptians chiefly, if not exclu- 

 sively, observed a heavenly body and the position of 

 other bodies in relation to it, when it was rising or set- 

 ting, so that it was absolutely essential that the body 

 which they were to observe should rise and set. Every- 

 body knows that as seen in England there are many 

 stars which neither rise nor set. The latitude of London 

 being 51°, the elevation of the pole therefore is 51°. 



Hence, any star which lies within that distance from 

 the pole cannot set, but sweeps round without touching 

 the horizon at all. The latitude of Thebes being 25°, the 

 distance from the pole to the horizon is much smaller, 

 and so the number of stars which do not rise and set is 

 much smaller. The stars which do not rise or set are 

 stars near the pole, and therefore stars which move 

 very slowly, and the stars which rise most to the 

 north and most to the south are those bodies which 

 are moving most slowly while they yet rise or set. 

 Can this slow rate of motion have had anything to 

 do with such stars being selected for observation, the 

 brightest star to the north, most slowly moving, the 

 brightest star to the south most slowly moving.? It is 

 possible that observations of these stars might have been 

 made in such a way that at the beginning of the evening 

 the particular position of y Draconis, for instance, might 

 have been noted with regard to the pole star: and 

 seeing that the Egyptians thoroughly knew the length 

 of the night and of the day in the different portions of 

 the year, they could at once the moment they got the 

 starting point afforded by the position of this star prac- 

 tically use the circle of the stars round the north pole as 

 the dial of a sort of celestial clock. May not this really 

 have been the clock with which they have been credited ? 

 However long or short the day, the star which was at first 

 above the pole star, after it had got round so that it was 

 on a level with it, would have gone through a quarter of 

 its revolution. 



In low northern latitudes, however, the southern stars 

 would serve better for this purpose, since the circle of 

 northern circumpolar stars would be much restricted. 

 Hence there was a reason in such latitudes for preferring 

 southern stars. With regard both to high north and 

 south stars then, we may in both cases be in presence of 

 observations made to determine the time at night. So 

 that the worship of Set, the determination of the time at 

 night by means of northern stars, might have been little 

 popular with those who at Gebel Barkal and elsewhere 

 in the south had used the southern ones for the same pur- 

 pose, and this may be one reason why the Theban priests, 

 representing Nubian astronomical culture and methods, 

 were pledged to drive the cult of Sutech out of the land. 



Since then the observations of y Draconis might be used 

 to herald the sunrise almost all the year round, and since 



NO. 1240, VOL. 48] 



the modern constellation Draco is the old Hippopotamus, 

 we can readily understand Plutarch's statement that 

 " Taurt presides over the birth of the sun," and why 

 Taurt or Maut should be called the Mistress of Darkness.' 



It does not seem too much to hope that the continua- 

 tion of such inquiries may ultimately enable us to solve 

 several points connected with early Egyptian history. 

 We read in Brugsch ; — ^ 



"According to Greek tradition, the primitive abodeof the 

 Egyptian people is to be sought in Ethiopia, and the 

 honour of founding their civilisation should be given to a 

 band of priests from Meroe. Descending the Nile, they 

 are supposed to have settled near the later city of Thebes, 

 and to have established the first state with a theocratic 

 form of government." 



" But it is not to Ethiopian priests that the Egyptian 

 Empire owes its origin, its form of government, and its 

 high civilisation ; much rather was it the Egyptians 

 themselves that first ascended the river to found in 

 Ethiopia temples, cities, and'fortified places, and to diffuse 

 the blessings of a civilised state among the rude dark- 

 coloured population." 



..." Strange to say, the whole number of the build- 

 ings in stone, as yet known and examined, which were 

 erected on both sides of the river by Egyptian and 

 Ethiopian kings, furnish the incontrovertible proof tnat 

 the long series of temples, cities, sepulchres, and monu- 

 ments in general, exhibit a distinct chronological order, 

 of which the starting point is found in the pyramids, at 

 the apex of the Delta." 



J. Norman Lockyer. 



{To be continued.') 



A PERIODIC MERCURY PUMP. 



I HAVE designed and constructed the instrument de- 

 scribed in the following lines to reduce the labour 

 of working pumps of the Sprengel class. It has proved 

 itself to be so serviceable in our laboratory that I believe 

 a short descripion of it may be useful to those who 



are engaged in work in which the mercurial pump is 

 employed. 



A is the cistern of the Sprengel pump (not shown), B is 

 a bottle having three necks : it is furnished with three 

 tubes, c, DD, EF ; C, which has a valve at i, is attached 



^ Rawlinson, i. 337. 



- " Egypt under the Pharaohs," ed. 1S91, p. 3. 



