10 
On those days, in which two observations were made, one with 
the face of the circle East and one with the face West, one equation 
is considered equivalent to two deduced from observations made on 
different days. Indeed, since the method of observing off the 
meridian has been generally adopted here, the result of two ob- 
servations of one day appears, as might be expected, more exact 
than the mean of two observations en different days. 
The equations of condition, in number 208, thus obtained, are 
given at the end of this paper ; and, doubling those when the circle 
was reversed, the number amounts to 333. 
These have been reduced to four equations, by the method of 
making the sum of the squares of the errors a maimum, viz. making 
(e+futgpthetk)+(etfetg'pthz+k)+ &c.a min. 
Taking the fluxions of these quantities, making e, «, p, and s vary 
separately, we obtain four equations. 
i Sg fh Sk 
9. f pet f ertsfe cpt fh est fk =—0 
&e &c &c &c &c 
g Sg gs gh fie 
3. gi pe t+ fo’ prt g® bot gl’ ez t+ gk =0 
&ec &e &c &C &c 
h Sh gh h? hk 
4 Wh pet fh pat gh pp + h? $s + hk =0 
&c &c &c &c &c 
