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ASTRONOMICAL PAPERS. 



117 



Chains. Log. 



Then NA difF. of lat. 1205.6648 3. 0812265 

 To AV. depart. 851,8436 3. 9303599 

 As Rad, TO. - - - 

 To Tang, of ENA the l]c of the ? J' 



couiic 35^\ 14'. 3y',o8 



'^34 



l»^ 



And Sine of 35*^, I4'. 33^^,08 9. 761204S 



To Rad. 10. - - - 



As 851,8436 a. 9303599 



To N£, the diflance in a ftrait 

 line™i476,2336 Chains. 



1691551 



But the coiufc of NE hcing 35'^. 14'. 33'/, E. with refpcd only to NA tJic magmil-. fmih / 

 *he variation - - - 3. 8. O 



add 



true meridian. 



Which gives 38. %%, 33 fi. for the courfe of NE with refpcdt to NS the 



So that the true courfe and diftancc from Norriton ohfervatory to Philadelphia 

 hi a ftraight hne, NE ii S. 38". %%'. 33'' E. 1476,^336 chains. 



ia ohfervatory, 



Then Rad. 

 To cofine of 



As NK 



To NS true difl". of lat. 



And Rad. 

 To fine of 

 AsNE. 



T© SE true diff. of long, 



38*, aa'. 33" 

 1476,2336 



38°. aa'. 33" 



I476,a336 

 916,47^3 



10. - - - 

 9. 8942913 

 3. 1691551 



3. 0634464 



10. - - - 



9. 79'^9637 



3. t^^SS^ 



a. 96aii88 



Norriton ohfervatory, 

 from PhiUid. ohfervatory, 



Tlius we have— 

 Chains. Feet, 

 North, 1x57,30^^76381,83=813'. 35'^ 7 difTcrencc oflatiiudc. 

 Wi'ft, 916,47=60^87, 02==oo'. 5z^^oftiine=:==l3' diff, of ]ongi 

 tude=9\95 of a great circle, or gcogra])hic inilc. 



But the ohfervatory in the Statc-Iioufe Square, 

 with refpe^t to the fouth point of the city of 

 Phihul (to which McflVs. Mafon & Dixon re- 

 fer their obfervations), is, 



Chain?!. Feet. 

 N. 40,o685=^a644,5!=s!26'',i6 diiT. of lat. 



W. a8,7695==^i898,8=»i'',6 of time. 



Therefore Non iton ohfervatory, with refpe^l to the foutherniaoR point of Philadelphia 

 jg Chains. Feet. 



North, 1157,30 4-4O06S5=^ii97,3^'^5— 79026,3^^13'. 01^86 difference of latitude, 

 Well, 916,47 -f2l8j7^'95^ 945^3395^^2385, B===oo'.53",6 of time. 



Hence, by the above meafurcment and work, wc get 

 Norrkon obfervatory 52'' of time weft of the obfervatory in 

 the State^houfc fquare; which is exadly what we got, by 

 that excellent clement, the external eontafi of Mercury 



Vol- I. 



ci 



with 



