56 



TRAVELS AMONGST THE GREAT ANDES, chap. hi. 



make the cisterns move from M to N — though^ if they did so, 

 the stands would not be overturned. The actual method of 



suspension at A, Fig. 2, is 

 a device of my own, and is 

 shewn in the accompanying 

 engraving, which renders 

 description unnecessary. To 

 set out a theodolite stand 

 and hang a barometer in 

 position upon this catch is 

 an affair of a few seconds, 

 while if the ordinary stand 

 is employed minutes are 

 occupied in the operation. 



The mercurial barometer 

 read 16*476 inches at 11 

 a.m. on Dec. 28, 16-488 

 inches on the 29th, and 

 16-480 on the 30th. Mr. 

 Chambers, at Guayaquil, 

 made simultaneous obser- 

 vations on the 28th and 29th, and found no change in pressure 

 on the latter day. But while the mercurials were demonstrating 

 the remarkable stability of the barometer in Ecuador the aneroids 

 showed lotvei"- pressures on each successive day. 



Dec. 28, 



Dec. 29 



Dec. 



Place of 





1879. 



1879. 



1879. 



Observation. 



Barometer. 



11 a.m. 



11 a.m. 



11 a.m. 







inches. 



inches. 



inches. 



Second Camp . 



Merc. Bar. No. 558 (corrected) 



16-476 



16-488 



16-480 



Guayaquil 



do. No. 554 ( do. ) 



29-910 



29-910 



. . . 



Second Camp . 



Means of six Aneroids 



15-643 



15-611 



15-577 



Do. 



Errors of means of Aneroids . 



-0-833 



-0-877 



-0 903 



Do. 



Aneroid F . . . . 



15-300 



15-300 



15-280 



Do. 



Error of Aneroid F • 



-1-176 



-1-188 



-1-200 



