1826.] Measurement of Heights by One Barometer. 87 



Mount Saleve, base ... . 28-393 (71i) 73J-\ .-)qo/% os^oft 



summit.. 25-707 (75^) 64/ "^^"^^ *• ~^'^^"' 



Lelth Pier 29-567 (554-) 54 \ r.r..,r ono 



Arthur's Seat 28-704 (51|-) 50^-/ ^^ "^ " 



Caernarvon Quay 29*984 (56-i) 554-") qcri Qorr.,- 



Snowdon Peak 26-271 (42a) 43 / '^^''^ ' • '^'^^^ "^ 



Keswick Lake (30 ft. ab.) 30-050 (61) 61\^-j,^ ^^-o 



Summit of Skiddaw.... 27-156 (57) 50 j~'^^ •' -'^ 



In the tables generally made use of by the author, the calcula- 

 tion is rendered more brief (at some slight expence of accuracy) 

 by the addition in Table II. of a third column, giving the value 



of — ^^th part of the preceding one, or the augmentation for 1° of 



the sum of the detached thermometers. The difference of the 

 increment per degree for any two given pressures being multi- 

 plied by the sura of the thermometers, we obtain the augmenta- 

 tion in altitude for temperatures above 0°. The quantities in 

 Tables 111. and IV. are calculated for the mean temperature of 

 50° F. To render the method more intelligible, an abstract 

 from the tables is given, together with a type of the calculation. 



1485-5 feet. Error - 1*5 feet. 



