76 M. Bouvard on the daily variation of the Barometer, 



Latitude. " ei ? ht in *? a ily Period 

 Toises. Obs. Calc. 



St Thomas's, 0°24' N. 1 ™.85 2.00 



Humboldt&Bonpl. 23°N.tol2°S 1500 2 .55 2.00 



La Condamine, Quito, 0° Lat. 1492 2 .82 2.00 



Duperry, Payti, 5° 3. 40 2.00 



Boussingault Sto Fe de ^ % 

 and Rivero, Bogota, 



Do. - - La Guayra, 10°36'N. 2. 44 1.90 



("Sier. Leone, 8°29N. 1. 82 1.94 



Given by J Trinidad, J0°39N. 1.57 1.90 



Mr Daniel, ( Jamaica> 170 56N . L 45 hn 



Brazil, Rio 



Dorta.Freycinet, Janiero, & fi 



and Lschwege, the Indian 

 Missions, 



Baron Von Buch, Canaries, 28° 8 N. 1.10 1.37 



Coutelle, Cairo, 30° 3 N. 1. 20 1.30 



A - - Rome, 41°54N. 0. 70 0.82 



Gambard, Marseilles, 43°18N. 0. 72 0.77 



Marque-Victor, Thoulouse, 43°34N. 1. 20 0.76 



Billet, - Chamberry, 45°34N. 137 1.00 0.69 



Ramond, Fermn^ 1 " 45 ° 46N ' 210 °' 94 °' 68 



Herrenschneider Strasburg, 48°34N. 0. 80 0.58 



M. A. Bouvard, Paris, 48°50N. 0.76 0.57 



Nell de Breaute, LaChapelle, 49° 55 R 0.36 0.53 



Daniel, - London, 51°31N. 0.38 0.48 



BesselandSommer,Konigsberg,54°42N. 0. 20 0.38 



Captain Parry, 74° 00 N. 0. 00 0.04 



In comparing these observations it is not easy to trace any 

 other law than that the daily variation diminishes from the 

 Equator to the poles. From the observations given by M. 

 Bouvard the mean amount for the Equator may be taken at 

 about 2.75 millimetres ; whereas in the table given by Mr Da- 

 niel it is only 1.85 millimetre. Taking the mean at two mil- 

 limetres or one-fiftieth of an English inch, the observations may 

 be pretty nearly represented by the formula, 



2 m x cos. 3 Lat. for millimetres, and 



Inch. 



0. 04 x cos. 3 Lat. for English inches. 



