Harmonic Analysis of Tidal Observations. 559 



tions in the working of the gauge, the gaps being 64 days in 1883, 

 64 days in 1884, and 14 days in 1885. 



It has already been remarked that the Ostend observations were 

 apparently well made, although, perhaps, not of the very highest 

 perfection. 



The results are referred to Ostend local time. 



Heligoland. 



The results for Heligoland are taken from Dr. Borgen's paper on the 

 Tides of South Georgia and Kingua-Fjord,* where they are given inci- 

 dentally as a means of testing a proposed method of reduction. The 

 observations appear to have been made in 1882, and the reductions 

 were, I believe, made by Dr. Borgen. The heights were given in 

 centimetres, but have been reduced to feet. 



Copenhagen, Nanortalik, Angmagsalik, Godthaab. 



I owe these observations to Dr. Crone, of Copenhagen, by whom, I 

 believe, the reductions were performed. 



The observations at Nanorfcalik and Angmagsalik were made by a 

 Danish Expedition between 1883 and 1885. At the latter station the 

 observations were very short, and Dr. Crone has only attempted to 

 determine the mean lunar interval of 4 h. 6m., or K of M 2 . 



The heights were given in centimetres, but have been reduced to 

 feet. 



The observations at Godthaab were made by the Danish Polar 

 Expedition of 1882-3; they extended from July 16 to August 31, 

 1883. 



Dr. Crone has written a paper entitled " Flux et Reflux de la Mer 

 a Godthaab." 



South Georgia and Kingua-Fjord. 



These observations were made by the Arctic and Antarctic expedi- 

 tions of the German Government. The observations in South Georgia 

 were made with a self-registering tide-gauge, those at Kingua-Fjord 

 by the officers of the ship. The observations were reduced by Dr. 

 Borgen, of Wilhelmshaven, and further information will be found in 

 the paper referred to above. 



The gauge was erected in South Georgia in January, 1883, and was 

 in operation until the end of April, when it was put out of order by 

 heavy weather. The observations began again on 21st May, and 

 continued until 2nd September, with breaks of only a few hours or of 

 a day caused by ice. The means of the values derived from the two 

 periods of observation are given below. 



* ' Separat-Abdruck au8 dem Deutschen Polarwerke.,' Asher, Berlin. 



