493 
of an Arc of the Meridian. 
53® 27' 31 ",59 for the latitude of Clifton ; and shall then have 
the difference of latitude between Barcelona and Clifton = 
12 0 5' 42", 79, something more than the 30th part of the whole 
circumference of the earth. With this difference of latitude, and 
the abovementioned distance, we shall get 60793 fathoms, for 
the mean length of a degree on the earth’s surface, in latitude 
47 0 24'. The latitude of Paris is 48° 50' 15"; this, with that of 
Clifton, gives 4 0 37' 1 £",59 for the difference between their 
parallels. The meridional distance is 1686593 feet; hence, 
60825 fathoms, is the length of the degree in latitude 51 0 9'. 
With regard to the latitudes of places published in our former 
papers, those referred to the meridian of Greenwich are to 
remain uncorrected, since the computations were made with 
nearly the same length of a degree on the meridian, as that at 
the middle point, now deduced, between Dunnose and Green- 
wich, viz. 60884 fathoms. As to those places referred to the 
new meridian, viz. Dunnose, Butterton, and St. Agnes Beacon, 
1 " is to be added to the latitudes of them all ; because the latitude 
of Dunnose became the standard, which was then computed 
to be 50° 37' 7", 3, but is now found, from the zenith distances 
of the stars observed there and at Greenwich, to be 50° 37' 8", 2, 
By way of Appendix to this Paper, I shall subjoin the latitudes 
and longitudes of those places intersected in the survey of 
Essex, Suffolk, &c. whose distances from their respective places 
of observation are given in the Phil. Trans, for 1800; this 
cannot but be highly useful, as they may be depended on, the 
interior survey of those parts having since proved that no erro- 
neous intersections were made. 
MDCCCIII, 
