320 Voyage of Capt. Sir James C. Ross to the Antarctic. 

 Magnetic observations were fully carried out, although during 



sixty-eight days while the ships were in Christmas harbor, it 

 blew a gale, generally with great violence ; for forty- five days 

 the establishment and observers were in danger of being carried 

 into the sea. 



Magnetic observations, May 29th and 30th. — The term-days 

 previously agreed on for simultaneous observations in all the for- 

 eign and British observatories, that constitute the great system of 

 magnetic cooperation, were here strictly attended to. 



" It happened fortunately to be a period of unusual magnetic 

 disturbance, so that the first days of simultaneous observations 

 proved the vast extent and instantaneous effect of the disturbing 

 power, affecting the magnetometers at Toronto in Canada and at 

 Kerguelen Island, nearly antipodal to each other, simultaneously 



and similarly in all their strange oscillations and irregular move- 



ments." The hourly observations were made without a single 

 break during the whole time the ships were at this island. 



The tides rise and fall here not more than thirty inches, and 

 the spring tides are generally less than two feet ; the neap tide 

 varies from four to twelve inches. 



July 20, 1840.— The ships left Kerguelen Island for Van Die- 

 mens Land. Terrific gales and snow storms attended them. 

 Once during a snow squall, the thermometer fell to 27°, although 

 the sea remained uniformly at 36° ; the vapor that rose from the 

 water at that temperature, almost instantly froze as it passed over 

 the ships, and kept them constantly enveloped in haze and snow. 



Many meteor appearances were seen during a heavy gale, July 

 27 ; there was much lightning, and the barometer fell to 28-88 ; 

 sheets of water broke athwart ships, flooding the decks — and July 

 30, Mr. Roberts, the boatswain, a man much valued, was swept 

 overboard and drowned, notwithstanding the daring efforts to 

 save him. 



During these gales the Terror parted from the Erebus, and they 

 did not meet again until their arrival at Yan Diemens Land. Ice- 

 bergs warned them to be vigilant during the Ion? cold and dark 

 nights of fifteen hours. The winds from the N.W. invariably 

 brought thick weather and snow showers, while clear cold weath- 

 er, with a rising barometer, attended the S.W. gales. 



Magnetic observations were regularly continued during the 

 whole distance of three to four thousand miles, from Kerguelen 

 island to Van Diemens Land; this was effected by means of the 

 excellent apparatus of Mr. R. W. Fox ; the instruments common- 

 ly in use would hardly have enabled them to make a single ob- 

 servation. They, several times, crossed the isodynamic lines, and 

 on August 6, found the maximum intensity to be in lat. 46° 44' S., 

 long. 128° 26' E., being then 2-034 (of the table, p. 104, vol. i), 

 and it diminished to 1-824 at Van Diemens Land. 





