60 Royal Society. 



laws of the phenomena as to the temperature and pressure of the 

 confined gas, will also soon be determined. 



Carbonic acid gas has been found to give a depression four and 

 a half times as great as atmospheric air, while it passes through 

 the porous plug with greater facility than atmospheric air ; equal 

 volumes requiring pressures of 1 and 1"05 respectively in order to 

 be transmitted in equal times. Certain heating effects of air rushing 

 through a single orifice have been observed, which will probably 

 lead to a further development of the mechanical theory of the tem- 

 perature of elastic fluids in rajjid motion. 



The examination of the sedimentary deposits in the Nile valley, 

 mentioned at the last Anniversary, is still going on. Mr. Horner 

 states, that by the munificent aid of His Highness Abbas Pacha, the 

 ^^iceroy of Egypt, a series of operations have been carried on at 

 Heliopolis, and at another station thirteen miles above Cairo, which 

 have led to interesting results. A pit has been sunk to the depth of 

 24 feet below the pedestal of the colossal statue of Ramses the 

 Second, who reigned, according to the chronology of Bunsen, about 

 1400 years before Christ, and borings have been continued by which 

 cylinders of soil have been extracted at an additional dejjth of 48 

 feet. A series of thirty-two pits has been sunk across tlie valley in 

 a line between the Libyan and Arabian deserts, occupying a line of 

 about five miles, passing through the site of the statue alluded to ; 

 and it is proposed to sink a similar line of pits next year about twenty 

 miles lower down the river, passing through the site of the obelisk 

 of Heliopolis. Above sixtj^ persons were employed in the operations 

 at Memphis. The plan, as proposed by Mr. Horner, was, through the 

 intervention of the Hon. Charles Augustus Murraj', Her Majesty's 

 late Consul-General in Egypt, submitted to the Viceroy, and met with 

 the most ready acceptance. He gave directions to his government 

 that every assistance should be afforded for carrying on the proposed 

 researches ; he appointed an able engineer officer high in his service, 

 M. Hekekyan Bey, to conduct them, and ordered that the whole 

 expense should be defrayed by his government. Such enlightened 

 liberality on the part of His Highness Abbas Pacha justly entitles 

 him to the gratitude of all cultivators of science. 



The other researches alluded to on the last occasion are proceeding 

 satisfactorily, but there is nothing which seems to call for especial 

 notice at present ; I will therefore at once proceed to give some 

 account of the steps which have been taken by your Council for the 

 advancement of science in another direction. 



In the history of individual sciences we perceive there have been 

 always successive periods of activity and rejiose. In Astronomy, for 

 many years we have had a period of activity. Physical Astronomy 

 has achieved perhaps its greatest triumph within the last few years 

 in the discovery of Neptune ; and the discoveiy of the numerous 

 Asteroids and Comets is evidence that Practical Astronomy has kept 

 pace with it. Within the same period the nebulous contents of the 

 Southern Hemisphere have for the first time been made known to us ; 



