208 report— 1842. 



Report of the Committee for the Reduction of Meteorological Obser- 

 vations. 



It was the earnest wish of your Committee to have made their final report 

 on this subject at the present meeting ; owing, however, to the severe illness 

 of Mr. Birt, to whom the execution of the reduction and projection of the 

 observations has been intrusted, and his subsequent change of residence, 

 together with the unusually early period of the meeting this year, it must be 

 deferred yet another year. Meanwhile the annexed letter from that gentle- 

 man will show the present state of the inquiry and the progress made : — 



"Western Literary and Scientific Institution, 

 47 Leicester Square, June 6, 1842. 



" Dear Sir, — I regret exceedingly that I am unable to send you a greater 

 number of the projected curves than those now inclosed, which nearly com- 

 plete the European series, including the British isles, during the years 1836, 

 1837 and 1838. The following are the stations omitted: — Greenwich, two 

 sets in 1836; Geneva, June 1837; Turin, March, June, September and 

 December 1837; Kremsmiinster, March 1838; Gibraltar, March and June 

 1837; and Cadiz, for 1837 and March 1838. The Turin curves were 

 omitted in consequence of the reduction of sidereal to mean time not having 

 been accomplished, and the remainder, with the exception of Greenwich, not 

 presenting those marked features of agreement which are so conspicuous 

 in most of the others. 



" I have just discovered that the European curves for December 1836 have 

 not been projected, and as the time of the meeting is now so rapidly approach- 

 ing, I have thought it best to forward those completed without waiting for 

 this sheet, which I will immediately proceed with. 



" I have not included the tables which I have been unable to complete, 

 principally in consequence of my illness during the autumn, which, with the 

 loss of strength resulting therefrom, prevented my close attention to them for 

 nearly four months. Had this not have occurred, I have no doubt the whole 

 of the projections and tables would have been completed by this time. 



" I inclose in this parcel the American curves formerly sent, — namely, De- 

 cember 1835, and March 1838, — as I considered it probable that you might 

 wish to see the contemporaneous observations on each side of the Atlantic. I 

 have also included South Africa and Asia for June 1836. 



" I have had no time on this occasion to look over the sheets previous to 

 sending them to you ; in the mere glance I have given them the curves of 

 December 1837 strike me as peculiarly interesting, especially the fall west- 

 ward and the rise eastward of Brussels. 



" Apologizing for the inconvenienee which I feel you will experience in 

 not having had the whole completed, 



" I remain, dear Sir, 



" Yours very respectfully, 

 " Sir John F. W. Herschel, Bart:' « W. R. Birt." 



Your Committee pray the continuance of the grant, on which no further 

 charges have been made this year. J. F. W. Herschel. 



In reference to the Report which had been requested from Mr. A. D. Baclie 

 of Philadelphia, relative to the meteorology of the United States of America, 

 Col. Sabine made the following statement to the Section. " Our valued 

 corresponding member Mr. Bache has requested me to explain to the Sec- 

 tion the causes which have prevented him from completing in time for the 



