154 LECTURE ON ARCTIC EXPLORATIONS. 



vessel was converted into a room for the men. The upper deck was 

 covered with a house made of boards, which had been brought for the 

 purpose. The ship's company lived in health and comfort. During 

 the autumn and winter the officers were engaged in various scientific 

 observations. 



Soon after entering our winter harbor an observatory was erected 

 upon shore near the vessel, under the superintendence of Mr. Sonn- 

 tag. It was a frame structure, covered first with canvas and then 

 with snow, and was eight feet square. In this a fine pendu'um appa- 

 ratus, constructed under Mr. Sonntag's supervision by the Messrs. 

 Bond, of Boston, after the plan of Foster's instrument, was imme- 

 diately mounted, and satisfactory sets of experiments were then 

 made by Mr. Sonntag, assisted by Mr. Radcliflf. The pendulum 

 beat nearly seconds ; that is, rudely, 3,(i07 beats in 3,600 seconds of 

 time. The readings were made when the knife-edge passed the zero 

 point of the graduated arc. The interval of the readings was ten 

 seconds, and eleven readings generally made a set. These observa- 

 tions were continued from September 26 until October 12. They are 

 yet unreduced, and I am therefore unable to announce to what con- 

 clusions the}^ lead. I may mention that experiments were made by 

 Mr. Sonntag and Professor Bond at the Cambridge Observatory prior 

 to the sailing of the expedition, and that the instrument will be 

 placed in Professor Bond's hands for a repetition of the experiments 

 at the same place. 



Upon removing the pendulum apparatus, a unifilar magnetometer 

 was mounted upon a firm support in the centre of the observatory, 

 and the scale readings were recorded hourly every seventh day, 

 and three times daily during the interval, from November to March. 

 The same instrument was subsequently used for making several sets 

 of experiments in declination, deflection, and vibration. A corres- 

 ponding number of sets of experiments for the determination of dip 

 were also made with a well-adjusted instrument. These four classes 

 of magnetic observations were, with certain omissions, subsequently 

 repeated at Cape Isabella on the west side of Smith strait, at Netlik in 

 Whale sound, at Upernavik, and at Godhavn. All of these observa- 

 tions are yet unreduced. I should mention that the instruments were 

 furnished to the expedition by Professor Bache, superintendent of 

 the United States Coast Survey, under whose supervision the con- 

 stants had been carefully determined, and to whom the instruments 

 will be returned for correction. 



Near the observatory a suitable shelter was erected for a number 

 of thermometers, which were read hourly every seventh day, and three 

 times daily in the interval. These instruments were carefully com- 

 pared at every 10° of temperature down to — 40°, and these records 

 were referred to a standard which was brought home, and has been 

 placed in the hands of the maker, Mr, Tagliabue, for further compari- 

 son. Some of the instruments were manufactured by Mr. Green, of 

 New York, and were furnished by the Smithsonian Institution. The 

 remain der were presented by Mr. Tagliabue. These observations 

 were continued during our stay at Port Foulke, from September. 1860, 

 to July, 18G1. I may mention in this connexion that throughout the 



