414 
inaccuracy and falsehood, which has often bee ? SuSlldve 
sacred writings, because they do not 
motions only. The meaning of words, he sa ys, « deter mi e^ y 
+>lp ; r nae ” an d Scripture employs them m their usual meamu 
iTl doubt whether the reVof his — - equally well- 
mf f/f — — w « - TO £ 
will be the difference of the second and first, of the thirteen^ 
twelfth of these twenty-five motions. 1 here will be 
Z SZ inc eased by t motion of A with reference to 
fmntv 1 bZT Weed immovable. This one quantity remains 
unknown Hence the relative motions cannot measure the abso 
Tut nor the absolute the relative. For the relatives plus*, an 
unknown and unknowable quantity, are themselves e a so , 
Z iZ and measures of the one must be measures of the n ^r alsu 
34. Again, the two helps suggested for learning the tr ue from 
the apparent motions, cannot really avail us. The ft ret :a thaUhe 
?o PP d" n :" “HsTaldl^his very diflereuce, the 
lk“ wh£i must be added to all the relative motmns.Jo 
" for^But the differences^ainly supply no help what- 
e i/°V£otohSpis sought in “the faces which are cu^es 
and effects of the true motions, as thus explained. , 
vlobcs kept at a given distance one from another by means > °* » 
c 0 rd were revolved around their common centre of gravity, we 
miVfrom the tension of the cord, discover the endeavom of &e 
crlobes to recede from each other and the axis of ;; > 
and thence compute the quantity of their circular motions 
Here however, all that would be proved is a relation be- 
tween a tangential velocity at right angles to the joining hne.and 
a^centripetal force, acting in the direction of that line Both of 
these are definite relations between the two globes, and n 
Either dobeto points fixed absolutely in empty space. Circular 
motion implies two bodies at least, an actual distance between 
them, and a line of junction If we conceive nreUbve movement 
of each, at right angles to that joining line, and in opposite dirt 
