"MAGNETIC INCLINATION AT GOTTINGEN. 641 
rather less confidence than those in the meridian itself, in which 
the influence of the above-named causes may be regarded as in- 
sensible. 
1b. 
The remaining six of the thirty-two original numbers may 
henceforth be designated as follows :— 
_ Values of L. For V — V°= 
IS 0 
180° — g, 180° — 9g’ 180° 
h, hi. 90° and 270°. 
Where the non-accented signs apply to B a north pole, and 
the accented to A a north pole, f, /', g. g! are the dips of the 
straight line joining the two extremities of the needle below 
the north horizontal line, for the positions in the magnetic meri- 
dian, f and/' being for the position in which the marked face of 
the needle is turned towards the east, and g and g’ for the con- 
trary position; A, i! are the dips of the same straight line in re- 
ference to the eastern or the western horizontal line, according as 
the marked face of the needle is turned towards the south or 
towards the north, the instrument being in the plane normal to 
the magnetic meridian. 
In regard to the elements on which these six quantities de- 
pend, g is quite constant, and 7 must be assumed equal for all, 
as we cannot take into account the small fluctuations which may 
take place during the course of the observations ; but Q, m, c 
alter their values after the poles have been changed; Q exactly 
180°; m and ce, so that they have no further definite relation 
to their previous state save that, if in changing the poles the 
manipulation has been the same, and powerful magnets have been 
employed, we may be sure that the differences cannot be great, 
nor in the case of ¢ can the absolute values be very considerable. 
As henceforth I let the non-accented signs Q, m, ¢ signify the 
definite values applicable to the observations with B a north 
pole, and replace them for A a north pole by Q + 180°, m! and 
c', the general equations of the last article transform themselves 
into the six following :— 
sin(f + ¢ — i) = cos (f + Q) per ye  neSintl, 2 .«(dis) 
sin(g — ¢— +) =£ cos(g ~ Q) > Fae C29) 
202 
