536 Decisions on Disputed Inventions and Discoveries. 



one, and in making reference to the motives of three gentlemen, whose 

 only error could be the annunciation of what they believed to be a new 

 fact in science, M. AragO has forgotten the courtesy which characterises 

 Frenchmen, and has used language which, in our country at least, has been 

 left to grace the oratory of the bar. 



If we suppose that M. Arago did really misunderstand the true and ob- 

 vious meaning of Colonel Wright's notice, he surely could not fir a mo- 

 ment believe that the three editors whom he censures were ignorant of the 

 daily variation of the barometer. With regard to the Editor of this 

 Work, he had it in his power to correct his mistake, by looking into 

 the Edinburgh Encyclopedia, (a work which he has quoted in some of his 

 papers,) in which he would have found the daily variation of the bar- 

 ometer treated of in more than one place. With regard to Mr Brande, he 

 could not but know that a gentleman like him, who held the important 

 office of Secretary to the Royal Society, and who even lectured on subjects 

 connected with meteorology, could not possibly be ignorant of the daily va- 

 riation of the barometer ; and with regard to Baron Ferussac, we have 

 every reason to believe that the subject is as well known to him as to 

 M. Arago. 



Now, if any reader shall be so dull, as to imagine that we attributed the 

 discovery of the diurnal variation of the barometer to Colonel Wright, or 

 so unjust as to suppose that Colonel Wright pretended to any such dis- 

 covery, we have only to assure them, that they have misinterpreted the 

 plainest language. 



We believe that this curious fact was first distinctly * noticed by M. Godin, 

 and that M. de la Condamine pursued the discovery. After having men- 

 tioned Godin's observations, Condamine remarks, — " Je trouvai que vers 

 le neuf heurs du matin le barometre etoit a sa plus grande hauteur, et vers 

 trois hcures apresmidi ale moindre: la difference moyenne etoit 1^ ligne." 

 — Jovrrial da Voyage, &c. p. 109. See also p. 50. 



From Godin's observations, the learned President passes immediately to 

 the labours of Humboldt, and terminates with those of the astronomers of 

 the Observatory, of which he himself is one ; but in all this display of 

 names, no English name appears ; and the labours of Mr Henry Trail, 

 Mr John Farquhar, (the celebrated proprietor of Fon thill, we believe,) 

 and Dr Balfour, so early as 1794, are left in utter silence. This blank, 

 however, we shall supply. Mr Trail had observed the daily variation in 

 India earlier than 179*. Mr Farquhar, in 1794, observes, 



" That after numerous observations, at all hours during the clay and 

 night, I found that the mercury is subject to the following variations, with 

 the utmost degree of regularity throughout the whole year. From C h a. m. 

 till about 7 and 8 a. m. it is stationary : It then rises till 9 a. jr. sometimes, 

 though rarely, till 10 a. m. when it becomes stationary till noon : It then 

 descends, and is lowest at 3 p. m. and continues stationary till S r. m- when 



• S» long ago as 1C60, Dr Beak observed that " very often, both in winter and 

 sumnicT, the mercury stood higher in the cold mornings and evenings than in the 

 warmer mid-day." Phil. Trans. No. !), p. 133, fee. 



