30 W. A. Norton on the Variations of the Declination 
equinoxes ; the same is therefore true of r. It will be seen in th 
sequel that the semidiurnal effect of the ecliptic currents, on th 
horizontal force, is twice as great at the equinoxes as at the su 
mer solstice ; from which it may be inferred that the actual } 
tensity of these conietie and therefore also the effect of the resi 
ual ecliptic str on the declination, (e) is twice as great 
the one epoch as the other. In the discussion of the vari 
tions of the horidbotel force it will also appear that the intensit 
of the ecliptic currents is nearly the same at the winter solstice 
at the equinoxes, but as these currents are in action at the zenith 
during only a little more than two-thirds of the semidiurnal interv 
at the winter solstice, I conclude, (taking all the circumstance 
into account, ) that the value of e will be reduced about one-hal 
at the winter solstice. To find r om the same epoch, we hav 
(p. 27) es 14: ve at eqnino at winter solstice. T 
approxima ues of r and abeing ne ound, eqs. (1) is (6 
(7), (13), (14), wi: (19), give the value an 
equinoxes and s , as well as of S a Dic mt 7 ee 
on ere ie re "Tabl e that there isa pretty close correspon 
e between the determinations of S and D, except in the ca 
in a Pet m=o, that is in which the radial currents in existene 
: g the ities ne 
in obtaining the formule, and to the eokabiiay hate assul 
tions made are only approximately t rue, we cannot undertake 
decide which, among the different stippositions made with rega 
to the values of m and n, corresponds most nearly to fact. We 
can only infer it to be highly probable that the radial curren 
in action at noon pass off almost entirely during the afternoo 
Since the value of e is taken the same at cach solstice, in eq. (17) 
n(e’—e’)=0; the values of S and D given by eqs. (17) and (19) 
are therefore independent of m, and w we can draw no inference 
(p. 207). No account was taken of the residual currents, aud 
We now see (p. 27) that the value of E comes out the same, at 
the equinoxes, whether these currents be taken into account of 
ry The value of Ei for the forenoon is 1-49; 2x1” AQ 
“98. The average values, for forenoon and afternoon, (wheth 
we use Table I or II,) is 2’ 02, 2X2'02= af ‘04. The actual 
flection is 3/23, 
