38 REPORT — 1841. 



Report of a Committee, consisting of Sir J.W.F. HERSCHEL,J5«r^., ikfr. 

 WHEWEhL.fthe Very Rev. theDE AN OF^i.\, Prof hijOYD, and Lieut. - 

 Col. Sabine, appointed for the purpose of superintending the scien- 

 tific co-operation of the British Association in the system of Simul- 

 taneous Observations in Terrestrial Magnetism and Meteorology. 



Your Committee, referring to their last Report for the history of the mag- 

 netic operations in progress up to the date of that Report, have to state, in 

 continuation, that the magnetic observatory at St. Helena was finished, and 

 the instruments established, in August 184-0, — at Toronto in September, — 

 and at Van Diemen's Land in October of the same year. The observatory at 

 the Cape of Good Hope also was completed and in activity at the commence- 

 ment of March in the current year, delays having occurred in its completion, 

 which, though productive of great uneasiness and distress to its officer in 

 superintendence, Lieut. Eardley Wilmot, could in no way be attributed to 

 any want of exertion, or to any negligence on his part. From each of these 

 stations returns have been regularly received since their respective dates of 

 completion. Previous to this, there have been received returns of seven 

 months of observation in a temporary observatory at Toronto, and of six at 

 St. Helena. All the observations, as soon as received, have been regularly 

 transmitted to Prof. Lloyd, and after examination by him, handed over to 

 Col. Sabine, under whose superintendence, assisted by Lieut. Riddell — the 

 state of whose health, unfortunately, has compelled his return from Toronto 

 — their publication will take place. Government having, on the application of 

 the Royal Society, taken upon themselves this additional expense. In conse- 

 quence of this arrangement, the reduction and printing of the observations 

 are now in progress. The portable observatories of the Erebus and Terror 

 were put up at Kerguelen's Land, and also at Van Diemen's Land. At the 

 former station, the May and June terms were observed — at the latter, those 

 of August and September 1840. During the stay of the expedition at these 

 stations, the magnetometers were observed hourly ; and the regular work of 

 the observatory at the latter station, under the direction of Lieut. Kay, has 

 been begun, and will be continued on this doubly-laborious plan of hourly 

 intervals for the ordinary observations ; while on the term-daj's, all the three 

 magnetometers will be observed at the same instants of time, at intervals of 

 2^ minutes, — the means of confronting this vast increase of labour being sup- 

 plied by the Colonial Government, as administered by that ever-active and 

 zealous friend of science, Sir J. Franklin. And in addition to this, and for 

 the sake of multiplying occasions of observing the correspondence of magnetic 

 perturbations with auroral discharges, one hour out of every 24 — viz. from 

 Ih. 50m. P.M. to 2h. 50m. p.m., Gottingen mean time, commencing from 

 January 1, 1841 — will be occupied with observations of the magnetometers, 

 at 2\ minutes' interval, in this order, viz. bifilar, declination ; vertical force, 

 declination ; bifilar, declination, V, D, B, D, &c. It is to be hoped that 

 some of the European observatories will, at least occasionally, furnish obser- 

 vations in correspondence with these. 



The reduction and publication of the observations made at the Van 

 Diemen's Land observatory and by Captain Ross's expedition have also, at 

 the request of the Admiralty and with the consent of the Master General of 

 the Ordnance, been placed under the superintendence of Lieut.- Colonel 

 Sabine. 



The first Report of the Director of the Madras Observatory (Lieut. Lud- 

 low), and the first month's observations, have been received. It commenced 

 regular observation on the 1st of January 1841. 



