Royal Society. 51 



nearly four times as great as that of ordinary oxygen, is contra- 

 dictory of my hj-pothesis concerning the nature of ozone. If, 

 however, we reflect that the experiments could only be tried 

 with oxygen containing comparatively little ozone, and that, in 

 order to convert this ozone into ordinary oxygen, the whole was 

 heated to 230'^ C. or more, it is easy to perceive how extremely 

 difficult it must have been to remove the disturbing influences 

 so far as to attain the requisite degree of accuracy. For this 

 reason, then, without in the least calling in question the skill and 

 care of the experimenters, I have, nevertheless, hesitated to at- 

 tach sufficient weight to the results they have found, to induce 

 me to suppress my hypothesis. 



VII. Proceedings of Learned Societies. 



ROYAL SOCIETY. 



[Continued from vol. xv. p. 550.] 



June 18, 1857. — The Lord Wrottesley, President, in the Chair. 



THE followiug communications were read :— 

 " On Hourly Observations of the Magnetic Declination, made 

 by Captain Rochfort Maguire, R.N., and the Officers of H. M. Ship 

 'Plover,' in 1852, 1853, and 1854, at Point Barrow, on the shores 

 of the Polar Sea." By Major-General Edward Sabine, R.A., D.C.L., 

 Trcas. and Vice-President R.S. 



Point Barrow is the most northern cape of that part of the Ame- 

 rican continent which lies between Behring Strait and the Mackenzie 

 River. It was the station, from the summer of 1852 to the summer 

 of 1854, of H. M.S. 'Plover,' furnished with supplies of provisions, 

 &c. for Sir John Franklin's ships, or for their crews, had they suc- 

 ceeded in making their way through the land-locked and ice-encum- 

 bered channel by which they sought to effect a passage from the 

 Atlantic to the Pacific. In this most dreary, and apparently unin- 

 teresting abode. Captain Maguire and his officers happily found an 

 occupation in observing and recording, for seventeen months unre- 

 mittingly, the hourl)'^ variations of the magnetic declination and of the 

 concomitant auroral phenomena, in a locality which is perhaps one of 

 the most important on the globe for such investigations. Their 

 observatory, placed on the sand of the sea-shore, was constructed of 

 slabs of ice, and was lined throughout with seal skins. The instru- 

 ments had been supplied from the Woolwich establishment, \vith the 

 requisite instructions for their use, and the observations were made 

 and recorded precisely in the same manner as those in the Colonial 

 Magnetic Observatories. The observations were sent by Captain 

 Maguire to the Admiralty, and were in due course transmitted to 

 General Sabine, by whom they were subjected to the same processes 

 of reduction as those in tlie colonial observatories : the results are 

 given and discussed in this communication. 



E2 



