MERIDIAN OX THE COAST OF COROMAXDEL. 15 1 



At the commencement, the old chain (with 

 which the measurement was made) exceeded the 

 new one hv nine divisions of the micrometer, equal 

 to "•";;^-^'^ feet. Therefore 100+ ""^^r' ^ 

 400 will he the measures in lengths of the new 



chain, equal 40001, 4420 



At the conclusion, the old chain 

 exceeded the new one by eleven di- 

 visions, consequently it had increas- 

 ed by wear two divisions of the mi- 

 crometer — 0,0008 feet. Hence '^^^ 

 x400=0, 1600 feet, is the correction 



for the wear, which add +0, 1^00 



Whence the apparent length of the 

 base, will be 400,010020 lengths of 



the new chain, 40001, ^020 



The sum of all the corrections in co- 

 lumn fourth for obtaining the ho- 

 rizontal distances, is 0,2^59, feet, 

 which must therefore be deducted • — 0,2359 

 And this will give the apparent hori- 

 zontal length of the base, in terms 

 of the new chain 400,013651 



lengths, or 40001,36661 



The mean temperature for the whole 

 base is 90'', 8 and the new chain 

 was measured off when the ther- 

 mometer stood at 50° lience to re- 

 duce the whole horizontal length .. 

 to the standard temperature of 

 62°, the equation will be expressed 



400,013661 feet, or 5,1162 feet 



which must be added, +5,1162 



Hence the whole horizontal distance 



corrected for 62° will be, 40^6,4823 



Which reduced to the level of the 



sea will be, 40006,4418 



L4 



