1854.] 



ACCOUNT AND RESULTS OF THE EXPEDITION TO EGYPT, <fec. 



179 



middle of the day that they cannot be got out, but are quite 

 loose in the cool of the evening. 



The Chairman observed, there was no doubt the expansive 

 action of the heat would always produce its full effect, either by 

 compressing the iron of the rails, or producing some motion or 

 distortion in their position. 



Mr. Norris said, that cases had occurred of the road becoming 

 hog-backed, rising with the sleepers out of the ballast, from the 

 want of sufficient allowance for expansion ; also in curves, the 

 rails and sleepers had been pushed bodily outwards in the bal- 

 last by the effect of expansion. The extreme change of length 

 in this country, from 80° or 90° variations of temperature, 

 amounted to a yard per mile, and this yard length must be dis- 

 posed of somewhere in each mile, either by sliding or tension, or 

 else by bending upwards or laterally, if there was not less re- 

 sistance to compression of the iron. 



Mr. C. Cowper remarked, that the extreme change of tem- 

 perature of 90° would cause a total strain on the iron of 6 tons 

 per square inch, at 1 ton for 15°, which amounted to the very 

 severe total force of 40 or 50 tons on the whole sectional area 

 of the rail of 7 or 8 square inches, to overcome any supposed 

 resistance. 



Mr. May thought the change of temperature in the rails 

 would be considerably less than that of the air, because they 

 were partly buried in the ground, and must therefore follow the 

 temperature of the surface of the earth, which fluctuated much 

 less than that of the air. 



Mr. Duclos remarked, that the expansion or contraction of the 

 rails would only take place from the mean temperature to the 

 maximum or minimum : and as the mean temperature of the 

 air in this country was about 50°, and the maximum 90°, 

 making a change in the air of 40°, the actual change in the rails 

 from the mean temperature was probably less than 30°, causing 

 a strain of not more than 2 tons per inch expansion or contrac- 

 traction. 



The Chairman observed, it was an important subject for 

 consideration, whether the allowance for expansion could be 

 entirely dispensed with; and the new chair appeared an im- 

 portant step in that direction, and might lead to doing away 

 with longitudinal bearings. 



Mr. Norris said that his attention had been first directed to the 

 subject of this chair about two years since, by the circumstance 

 of a very extensive alteration having been in contemplation from 

 the ordinary rail and cross sleepers to a bridge rail on lon- 

 gitudinal timbers, the alteration being proposed entirely on the 

 ground of obtaining a superior coupling of the joints with the 

 longitudinal bearing than the ordinary rail and chair. But 

 he objected to the bridge rail and longitudinal timbers as 

 more expensive; and the idea then occurred to him of run- 

 ning the melted metal into the chairs to fill them up solid, 

 and make a rigid coupling of the joint; and this led him to 

 casting the joint-chairs solid upon the rails in their places, as 

 the complete way of carrying out the object. 



Preliminary Account and Results of the Expedition of Dr« 



Richard Iiepsius to Egypt, Ethiopia} and the 



Peninsula of Sinai** 



The fertile and extensive province of Dongola, on the northern 

 frontier, which we traversed on the 4th of June, after our departure 



* Extracted from " Letters from Egypt, Ethiopia, and the Peninsula of Sinai," by 

 Dr. Ilichard Lepsius. — Continued from page 152 



from Barkal, afforded us but few remarkable ancient remains; we 

 may, however, mention among these the Island of Argo, with its 

 monuments, from the 13th Manethonic Dynasty. They became 

 still more numerous in the northern borders of Dongola, from 

 which a nearly continuous cataract country extends as far as Wadi 

 Haifa. Near Tombos we found traces of the Egyptian dominion 

 under the Pharaohs of the 17th and 18th Dynasties, rock-tablets 

 with the shields of the two first Thuthmosis and of the third 

 Amenophis. Farther on, at Sesebi, there were the remains of 

 temples of the first Sethos of the 19th Dynasty. The great 

 Temple of Soleb, built by Amenophis 3rd and 4th, detained us 

 five days. The ruins of the Temple of Sedeinga, and those upon 

 the island of Sai, belonged to the 18th and 19th Dynasties. 

 Opposite this island stood the remarkable Temple of Amara, 

 which was built by the Kings of Meroe and Naga, and is still an 

 important proof of the extent of their dominion. 



Semneh was the next point, we reached. The Nile is here 

 compressed within a breadth of only about 1150 feet, between 

 high rocky shores. On both sides there are ruins of old Temples 

 of the 18th Dynasty. But these were not the earliest buildings 

 which were erected here. We found a considerable number of 

 inscriptions from the 12th and 13th Manethonic Dynasties, espe- 

 cially on the large foundations of the Temple of Kummeh, situated 

 lower down, opposite Semmeh on the eastern bank, as well as on 

 the scattered rocks on both banks in the neighbourhood of that 

 Temple. Many of them were intended to indicate the highest 

 risings of the Nile during a series of years, especially in the reigns 

 of the Kings Amenemhe 3rd and Sebekhotep 1st, and by com- 

 paring them, we obtained the remarkable result, that about 4000 

 years ago the Nile used to rise at that point on an average twenty- 

 two feet higher than it does at present. This, therefore, which 

 we saw before us was the most ancient Nilometer, and the earliest 

 statements of the heights, and their greatest number, were recorded 

 during the reign of the same Kino;, the Moeris of the Greeks, 

 with whom we had already become acquainted in the Faium, as 

 the great hydraulic architect. The strong fortifications on both 

 banks of that narrow part of the river convinced us at ODCe that, 

 during the early times of the 12th Dynasty, this remarkable point 

 served as the boundary of the Egyptian dominion, against the 

 Ethiopian nations who dwelt more to the south. 



At Wadi Haifa, on the 30th of July, we again left the cataract 

 country, remained from the 2nd to the 11th Aug. in Abu Simbel, 

 examined until the end of the month the ruins of Ibrim, Anibe, 

 Derr, Amada, Sebua, Dakkeh, Kuban, Gerf-Hussen, Sabagura, 

 Dendur, Kalabscheh, Debot, and spent the whole of the following 

 month in examining the monuments of the island of Philse, and 

 the islands of Bigeh, Konosso, Sehel, and Elephantine, surrounding 

 it, and of the stone quarries between Philas and Assuan. October 

 was spent visiting Umbos, the two Silsilis, Edfu, the desert Tem- 

 ple of Redesieh, El-Kab, Esneh, Tod, and Erment. 



On the 2nd of November we again arrived on Theban ground, 

 and first visited the rock-tombs of Qurnah, on the west side, where 

 we remained nearly four months, till the 20th of February, 1845, 

 when we encamped for three more months at Karnak. The 

 number of monuments of all kinds both above and below ground 

 at Thebes, is so great that they may be truly called inexhaustible 

 even for a combined power like ours, and for the limited portion 

 of time which we were able to devote to their investigation. But 

 the age of the monuments at Thebes, is almost exclusively limited 

 to the New Monarchy ; and the most ancient we discovered, such 

 as one might generally expect to find, are not earlier than the 1 1th 

 Manethonic Dynasty, the last but one of the old Monarchy ; for 

 this simple reason, because it was in this Dynasty that Thebes 



