HISTORICAL NOTE. 



HISTORICAL NOTE. 



BY 



DR. CHARLES CHREE, F.R.S. 



THE tabulation of the Magnetic Curves registered at the Winter Quarters of the National Antarctic 

 Expedition between March, 1902, arid January, 1904, was commenced in the Observatory Department of 

 the National Physical Laboratory in December, 1904. The material consisted of photographic records of 

 Magnetic Declination, Horizontal Force and Vertical Force for some 600 days. For the first six months 

 the work was carried out by Mr. L. C. BERNACCHI, who had been in charge of the magnetographs of the 

 Antarctic Expedition. He went carefully through the curves, and decided the exact times of starting and 

 stopping registration on ecich day by reference to the daily notes he had made in the observation books and 

 the register of watch- and chronometer-rates. He also tabulated, with the assistance of Mr. B. JOHNSON, 

 a large portion of the records of Magnetic Declination. On Mr. BERNACCHI'S relinquishing the work it 

 was entrusted to Mr. H. A. MAUDLING, who carried it on, with Mr. JOHNSON'S assistance, until he left for 

 another post in the summer of 1906. He was succeeded by Mr. A. E. GENDLE, who continued the work 

 until his appointment, early in 1908, to Eskdalemuir Observatory. The completion of the work was then 

 entrusted to Mr. B. FRANCIS, Librarian in the Observatory Department, who, with the assistance of 

 Mr. F. LEVIN, brought it to a conclusion. 



In addition to the tabulating work, the assistants mentioned carried out a great deal of arithmetical 

 work, in connection more especially with the tables of Diurnal Inequalities and the calculation of Fourier 

 Coefficients. Whilst the repeated changes in the personnel tended to delay the work, and interfered, 

 possibly, to some extent with its continuity, there was the compensating advantage that the checking of 

 the measurements almost invariably fell to a new and unprejudiced observer. The fact that under these 

 circumstances few serious mistakes were discovered encourages the belief that a high standard of accuracy 

 was maintained. During 1908 a good deal of photographic work in connection with the reproduction of 

 the Antarctic curves was done by Mr. W. J. BOXALL, a senior assistant in the Observatory Department, 

 and a good many other curves were copied with the Schmidt tracer at Bushy House, by Mr. W. II. BROOKES, 

 under the supervision of Mr. F. J. SELBY. 



My work has been much facilitated by the care exercised by all these gentlemen. To Mr. BERNACCHI 

 I am particularly indebted for the trouble which he has taken throughout the whole course of the work in 

 assisting in the removal of sources of uncertainty on which he alone could throw any direct light. 



Thanks are also due to Dr. COLERIDGE FARR and Mr. H. F. SKEY, successive Directors of Christchurch 

 Observatory, New Zealand, to Mr. C. T. F. CLAXTON, Director of the Royal Alfred Observatory, 

 Mauritius, to Mr. N. A. F. Moos, Director of the Colaba Observatory, Bombay, and to Mr. E. KITTO, 

 Superintendent of Falmouth Observatory. In response to an appeal issued by the Royal Society's 

 Antarctic Magnetic Committee, these gentlemen put at my disposal, in the most generous way, copies or 

 originals of the records of a number of magnetic disturbances, synchronous with disturbances recorded at 

 the Antarctic Winter Quarters. The extent to which the work has benefited by the co-operation of 

 these gentlemen will be appreciated only after a study of Chapters VIII and IX. Valuable as was the 

 contribution of copies of disturbed curves from Christchurch Observatory the nearest observatory in 

 existence to Winter Quarters it represents but a small part of what has been done by Dr. FARR and 

 Mr. SKEY. In his anxiety to utilise to the full the opportunities presented by the Antarctic Expedition, 

 Dr. FARR extended the scheme of co-operation arranged with the German Antarctic Expedition and 

 co-operating Observatories, to the extent of running the Christchurch magnetographs at high speed 

 during the whole 24 hours of the two monthly " term " days, so as to secure a very open time scale. 

 Mr. SKEY had all these quick-run curves tabulated at 1-minute intervals and part at 20-second intervals, 

 and the results of all these measurements were sent to this country, along with photographic copies of the 



