1850.] by the Barometer. 395 



Extract the Barometric Factors from Table II., then according as 

 the Barometer at the lower station is more or less than 30 inches, 

 multiply the sum or difference of these Factors, by the Factor for the 

 sum of the temperatures from Table III. The result will be the differ- 

 ence of altitude in feet. 



Where great accuracy is desired a small correction for the approxi- 

 mate Latitude of the place may be applied from Table IV. This is to 

 be added to or taken from the computed height, according as the La- 

 titude is less or more than 45°. 



Thermometers, 

 Barometers, attached, detached. 



Example I. Calcutta, 30.131 87 86 



Hazaribagh, 28.019 78 77 



Diff. 9 Sum 163 



Barometer at the colder station,. . 28.0 1 9 

 Correction Table I. for Bar. 28, 



and Diff. 9, 028 



28.047 Factor Table II. 29.23 

 Barometer Calcutta, .. , r 30.131 „ 1.89 



Sum of the Factors, 31.12 

 Sum of Thermometer 163°. Factor from Table III. 66.98 



24896 

 28008 

 18672 

 18672 



Product, Hazaribagh above Calcutta, in feet, 2084.4176 



Here it will be observed that the Barometer at the lower station 

 exceeds 30 inches ; therefore the sum of the Barometric Factors is used. 

 The Latitude of Hazaribagh being 24° and the elevation 2000 feet, it 

 appears from Table IV. that 3 feet may be added to the above result. 



