the mean Denjlty of the Earth. 713 
Loth of thefe methods then, and by all the triangles 
furnifhed by each of them, 1 computed all the princi- 
pal lines in the plan, and either took a mean among the 
feveral values of each, or elfe fele£led out of them fuch 
one as from various circumftances I judged it fafeft to rely 
upon, as neareft the truth. The trigonometrical compu- 
tations were always accurately made, and generally re- 
peated by logarithms, and the refult of every proportion 
determined to two or three places of decimals. I fhall 
here abftraft the mean or corrected values of fome of 
the principal lines or horizontal diftances fo computed, as 
well as the fecondary bafe kn from the Eaftern to the 
Weftern cairn. 
The mean among a great number of ways of compu- 
tation from the South bafe gives the horizontal diftance 
from k to N = 405a*2, and the mean of all the refults 
from the North bafe gives kn = 4058*9, and the 
mean between thefe two gives 4055*5 for the mean 
diftance of k and n. And this value of kn was ufed in 
computing moil of the other lines, whofe mean refults 
are as here follows. 
4 T 
v,y~ 
Vol. LXVIII, 
