30a. • MEMOIR RELATIVE- TO' 



\./ ■„ ;.. ;■:, ^ : ■ XI. XM. XiU. Xff;- 



jMofe-ra-Spur 7o»^.'' Feet 2i)0ig6' 22724,4 2i684,0 g4904,i-i 



Abo*-® tail Mai 'III .ooc Dit'o !4i69,2 16845 6 16895,8 1925?,?. 



Q&li/Mat'li.atooTe fa/l, 0r Di-tto 5750, 4 ■ 5-378.8 S7«8,5 565S,e 



I'isB ni«',a,ii of Hie foor. g'^e 'lie hfiigbtli of ( all .MWh al*o»»-€as'ipiir ,.., 8767 Feed 



Assumed hfighth <>f Ca-'ipur above the sea ,,o(> ea«» 650 Ditto 



■I^HE' preceding dificrences, fbpuld, Q,f couTfe, -be exadily- equal ■-(© caeb 

 o,tljer, bat.tbe uncertainty with refped to the refraftlon due, together 

 with the poiTible errors of obferifation, at both ftations, are more than- 

 fuiEcient to account for the e^^isting difcrepancy. The mean of the 



whole is taken as the heighth of Cdit Math above the plains of Rohil^ 

 khand^ and Csf/^Mr -is edJ-ma-ted to be §50 feet above the feaj whick 

 csiauot- l):e. ¥£iry widg. .of die truth, ^ 



^^.^.^f^- the heighths of -places- within the^hiils, have been referred fo^. 

 this ahitude of Call MaCh, either diredly, oi*wi<b intermediate ftatians \ 

 alfo -rV of the intercepted arch, has been uniformly allowed for theeffedb 



oCyXefra^ion, iii computing <he altitude of fnowy peaks, and ^^^ of the 



-fajmerMP^i.. /c^-f-.-S-ll P'^ints below ihs iaferior-h-mit of eo'ogeiation^ 



;lT.-,.,is atptefent.my opinion, tha.t both-tKefc qua mi ties exceed the ■ 

 medium effe 61, , of refraction 5- yndar- th^., .circmra-ftajises, in which the 

 obfervations are oiadCs .and though it is not neceilkry to exaggerate 

 h^i^hths, ^Ir^ady enoraioa*, 1 arn inclined to believe, tha^t all the eleva« 

 tii^ns;^:rir-a -litiieJa defed, m coBiequeoce of having ufed them. 



Ir remaias-to^ew exarr/ples-of the cafes I have fuggefted, in which 

 the known pofitions of fnowy peaks n^ay be ufefully applied to the 



CQisnedion of geogr-aphicaf maps-j con{iifu.ded-from perambtitator mJ5%^^ 

 (orements. 



