THROUGH FINLAND. 
377 
u found and perfevering refearches. The philofopher, animated 
“ by the principle which is charadteriftic of human reafon, and 
tc which uniformly tends to refer all knowledge to one point, to 
“ reduce it to lyftem, and to colled!: the wdiole as into a focus, 
te whence he may at one view' furvey the vaft field of natural 
“ phenomena, perceives here a fource of difcoveries for perfedt- 
“ ing to a great degree all the branches of real knowledge, and 
ec will endeavour to accomplifh his objedt, at whatever expence 
of labour and time it may coft him. But this interefl w r ill be- 
e< come ftronger, in proportion as he finds the relation which 
“ thefe purfuits, of great importance in themfelves, all bear to a 
“ queftion, the folution of which is ftill a fecret; namely, the 
“ queflion that has been fo much agitated, refpedting the figure 
“ of the earth. The navigator has every moment occafion to 
“ know what point he occupies on the furface of the globe. For 
“ this purpofe, having obferved any one phenomenon in the hea- 
e( vens, (we will fuppofe the diflance of the moon’s centre from 
“ a particular ftar) he ought to be able to determine by calcula- 
“ tion, how this fame phenomenon w r ould appear to the eye of 
ec an obferver placed at the center of the earth. Confequently 
“ into this calculation, the equation of the earth’s furface enters 
“ as an element, which, not being known with fufficient accu- 
“ racy, might eafily give occafion to an error of fome feconds ; 
“ and aftronomers are not ignorant of w’hat moment fuch an 
“ error might prove. It was with a view to difembarrafs the me- 
thod of finding the longitude at fea from thofe uncertainties, 
Vol. I. 3 C that 
