GENERAL INDEX. xix 



PAGE 



Table XVI. Height, in English Feet of a column of air corresponding to a 



Tenth of an Inch in the Barometer ..... 427 



" XVII. Height, in French Feet of a column of air corresponding to a 



Paris Line in the Barometer ...... 427 



" XVIII. Height, in Metres of a column of air corresponding to a Milli- 

 metre in the Barometer ....... 427 



" XIX. Height, in Metres of a column of air corresponding to a Milli- 

 metre in the Barometer at different Temperatures and Eleva- 

 tions . . 429 



" XIX'. Height, in English Feet of a column of air corresponding to a 

 tenth of an inch in the Barometer, at different Temperatures 

 and Elevations ......... 430 



" XX. Correction to be applied to the means of the Hours of Observa- 

 tion to obtain the True Mean Barometrical Pressure, Phila- 

 delphia 431 



" XXI. Correction to be applied to the means of the Hours of Observa- 

 tion to obtain the True Mean Barometrical Pressure, Green- 

 wich 432 



" XXII. For reducing Minutes into Decimals of an Hour . . . 433 



" XXIII. Correction for curvature and refraction 434 



Thermometrical Measurement of Heights. 



" XXIV. Regnault's Barometric Pressures corresponding to the Tempera- 

 ture of Boiling Water 438 



'' XXV. Regnault's Barometric Pressures corresponding to the Tempera- 

 ture of Boiling Water, revised by Moritz, in metrical mea- 

 sures ........... 442 



" XXVI. Regnault's Barometric Pressures corresponding to the Tempera- 

 ture of Boiling Water, revised by Moritz, in English measures 444 



V. GEOGRAPHICAL MEASURES 447 



a.} Comparison of the measures of Length most generally used for indicating 



altitudes 449 



Table I. Conversion of French Toises into Metres . . . .460 

 " II. Conversion of French Toises into Paris Feet .... 460 



" III. Conversion of French Toises into English Feet . . . 461 

 " IV. Conversion of French Toises into Rhine Feet . . .461 



" V. Conversion of Metres into Toises . . . . . 462 



" VI. Conversion of Metres into Paris Feet 463 



" VII. Conversion of Metres into English Feet .... 466 



" VIII. Conversion of Metres into Rhine, or Prussian Feet . . 474 



" IX. Conversion of Metres into Feet of Vienna .... 474 



" X. Conversion of Paris Feet into Toises ... . 475 



