336 Proceedings of the British Association. 



Ministry of the Marine, all which instruments, through the effi- 

 cient intervention of M. Arago, it is understood will be placed at 

 the disposal of the observer or observers who may be appointed 

 to conduct the observations. To complete the establishment, 

 however, certain instruments, as well as registry-books, &c. are 

 still requisite. The Council of the Royal Society have under- 

 taken to supply these from the WoUaston Donation Fund.* As 

 regards the magnetic observatory at Breslau, under the direction 

 of M. Boguslawski, your committee have to report, that in order 

 to secure the establishment of that station, and to place it on an 

 equal footing with the rest, certain instruments, &c. required to 

 be provided, for which no funds existed or could be made avail- 

 able on the spot, viz. a bifilar and a vertical-force magnetometer, 

 with the requisite reading telescopes, and a set of registry-books. 

 * * These were supplied at the expense of the Association. * * 

 A letter from M. Boguslawski, dated July 22, 1840, announces 

 the safe arrival of the instruments and books in question, and 

 the consequent complete state of instrumental equipment of the 

 Breslau observatory, expressing at the same time, his sincere 

 thanks for the assistance accorded him. By returns from the 

 several stations authorized by the British government, so far as 

 yet received, it appears, that the observatories at the Cape and St. 

 Helena might be expected to be complete and ready for the re- 

 ception of the instruments in May. From Van Diemen's Land 

 no accounts have yet been received. At Toronto, Canada, where 

 the greatest delays and difficulties were to be expected and have 

 been experienced, the observatory was so far advanced at the 

 date of Mr. Riddell's last communication, as to leave no doubt of 

 its completion in time for the regular observation of the August 

 term.f Meanwhile, in this, as at the other stations, all observa- 

 tions practicable under the actual circumstances of each are made 

 and regularly forwarded ; and here your committee would espe- 



* An interesting view of the existing state of knowledge respecting terrestrial 

 magnetism, and a detailed account of the present magnificent system of magnetic 

 observations, is contained in a paper in the (London) Quarterly Review, July, 

 1840, No. 131, Vol. 66.— Eds. 



t On the te7-7n days, which begin on the Friday preceding the last Saturday in 

 February, May, August and November, at lOA. P. M. Gottingen mean time, the 

 magnetic observations are continued for tvvenfy-four successive hours, at intervals 

 of tioo and a half minutes. Similar observations are also made on the Wednesday 

 preceding the 21st of each remaining month. — Eds. 



