NaturaUUistorical Collections. 53 



progressive accumulation of them for ages ; for, in an always equable climate, 

 buildings made of granite, last until they are purposely destroyed. It must be 

 remembered, that Egypt being mistress, by her position, of the commerce of 

 Africa, must have acquired immense riches, and that all these riches she must 

 have employed in the valley of the Nile, as beyond it there was nothing but sand. 

 Being thus unable to extend her territory, she covered it with palaces. A like 

 union of circumstances produced similar results at Palmyra, which is a green 

 oasis placed in the midst of the desert. It possessed no other advantage than that 

 of having a kvr springs ; but this was enough to bring to it, in their passage, 

 the caravans which travelled from the Euphrates to the Mediterranean. These 

 caravans came laden with the valuable productions of the East ; and during their 

 short abode in the oasis, they left there much gold, of which the inhabitants could 

 have made no use, had they not employed the greater part of it in raising temples 

 and palaces. 



In modem times, Genoa, in like manner, enriched by commerce, and confined 

 in her territory by the sea and the Appenines, has, in some measure, reproduced 

 the wonders of Palmyra and Egypt. 



Egypt, during the whole time of her prosperity, remained shut to strangers ; 

 but about the sixth century before our era, disturbances having arisen, and having 

 brought on a civil war, the weaker party sought assistance from without, and 

 Psammeticus was the first who brought auxiliary troops from Asia Minor. It 

 was then only that the Greeks were enabled to profit by the advances which tlie 

 Egyptians had made, and that Thales and Pythagoras, and perhaps several 

 other sages, whose names have not been preserved, went to be instructed in the 

 school of the priests. 



To judge of what the Greeks must have gained by this communication, it is 

 necessary to know what was, at this period, the state of science in Egypt. Let 

 us, in the first place, see what progress had been made in the mathematical sci- 

 ences. 



It is certain that the Egyptians had some knowledge of hydraulics, since they 

 were expert in the art of digging canals ; that they had ideas of mechanics, since 

 without very powerftil machines it would have been impossible for them to erect 

 their obelisks, and to raise the enormous blocks which some of these monuments 

 present. It is certain that they had pretty accurate procedures in stereometry, of 

 which a proof is to be found in the shape of the stones of their buildings. We 

 know, further, that they were expert land-surveyors. All this would lead us to 

 believe that they had advanced considerably in the mathematical theories. But 

 on the other hand, if it is true that it was Thales who first taught the priests to 

 calculate by the length of the shadow the height of one of their pyramids ; if it is 

 true it was only after returning from one of his journeys that Pythagoras discovered 

 the theorem or the square of the hypothenuse, it must be admitted that the geome- 

 try of the Egyptians was still in its infancy, or at least that it was purely prac- 

 ticaL 



At the period when the first emigrations to Greece took place, astronomy had 

 made very little progress in Egypt, as the lunar year alone was known there. But 

 as this science, as we have said, was very necessary to the Egyptians, they applied 

 to it with great perseverance, and made rapid progress in it, so that, when the com- 

 munication was re-established with the Greeks, in the reign of Psammeticus, 

 they had already adopted the solar year of 365 entire days. Soon after they even 

 made addition of a fourth of a day, and thus came much nearer the true duration. 

 This reformed solar year was employed for civil uses. As to the religious 

 year, it having been regulated at an earlier period, it remained with its 366 

 complete days, without its being permitted to be changed in the least. There 

 resulted from this that the festivals were gradually displaced, — that they no 

 longer corresponded to the same sideral periods as at the time of their insti- 

 tution, — and that, to come back to them, they had successively passed through 

 all the seasons. This period, at the end of which all came back to the ori- 

 ginal order, was what the Egyptians named the great year) or the year of Syrius. 



