6io Mr. Dalby’s Remarks on Gen . Roy’s Account 
3° 35' 42 v . 3 in the proportion of 61225 to 60811.7, we have 
3 34/ i4 /7 .9 for the value of that arc when 6122^ fathoms is 
= i° ; hence cofine 48' 34' 35" : rad. :: fine 3 0 34' 14''. 9 : fine 
5 0 2 4 / 6 7/ , the other longitude of Stratbourg. By the latter 
method the longitude of Cordouan was computed ; but the 
other longitudes according to the former. The diftances from 
the meridian of Paris are to be found in the publications 
alluded to in the above page. 
P. 232. In the Table of General Refults, for i° 8' 9" and 
4m. 32s. 36th .put i° 8" 4" and 4m. 32s. 1 6th. 
the longitude of Padlefworth. 
Againft Calais, for 7 m. 23 s. 15.8th. put 7 m. 23 s. 
1 5.2th. 
Againft Fairlight Down, in the laft column but 
two, jor 539.5 put 593.5. 
P.239. 1 5. fir fig. 12. put fig. 13. 
P. 242. 1 . 10. from bottom, for f 55^ put fig. f 35". 
P. 243. 1 . 13. for OKT put OK/. 1 . 5. from bottom, for 
kt put kL. 
P. 224. 1 . 1 1. for put 7 J. 
1 
In the Table facing p. 246. in the column of mean refradhon , 
for c/ 1 5". 4 put i' 28 // .i. 
In addition to the examples of refra&ion in SeCt. VII. the 
following (which was overlooked when this part was drawn up) 
may not improperly be given, as being of a different kind. It 
fhews, thatterreftrial refraCtion (though often muchgm7/£r)muft, 
at particular times, be much lefs than is generally fuppofed. 
OCt. 7, 1787, at the ftation near Padlefworth, the depref- 
fion of the horizon of the fea, in a SW direction nearly, was 
obferved 26 7 A degree of a great circle in this direction 
is about 61000 fathoms, and therefore 61000 x 6 x 57.2957795 
1 
