ine the exact longitude of the initial point, having
given the figure 19 deg. 55' 3" west of Paris, the geographer, Delisle,
for the sake of simplicity, adopted the round number 20 deg.; and, as I
stated a little while ago, this alteration completely changed the
character of this prime meridian. It ceased to be neutral, and became
merely the meridian of Paris disguised, as has been truly said, and
the English, notably, never adopted it. Here is the difference,
gentlemen, between a neutral meridian and a national meridian.

And, parenthetically, you see, gentlemen, how dangerous it is to
awaken national susceptibilities on a subject of a purely scientific
nature. Now allow me to add that, if in 1633 it was possible to find a
neutral meridian, a purely geographical meridian, an independent
meridian, it may easily be done in 1884 if we wish to do so; and that
a point chosen on purely geographical considerations, either in
Behring's Strait or in the Azores, could be much better determined now
than was possible to Father Feuillet in 1724, and could take the
position which the meridian of Ferro would not have lost had it not
been confounded with the meridian of Paris.

Professor J. C. ADAMS, Delegate of Great Britain, stated that he
merely desired to refer to one subject touched on by the Delegate of
France, Mr. JANSSEN, whose opinion he thought could hardly be
supported, and that was that the question of longitude was purely one
of geography. He desired to controvert that, and to hold that the
question of longitude was purely one of astronomical observation. The
difference of longitude between two places could not be determined by
geodetic observations, because to do this you must take hypothesis as
to the figure of the earth, and the figure of the earth is not a
simple figure. You may take as hypothesis that the figure of the earth
is spheroidal, and that the ratio of the axes is exactly defined. Now,
in the first place, we are not agreed as to the exact ratio of the
axes, nor are we agreed as to the exact figure of the earth. If an
attempt is made to measure the difference of longitude between two
points on the earth's surface, especially when they are a considerable
distance from each other, it is necessary to depend upon astronomical
observations. In attempting to deduce the difference of longitude from
geodetic measures, you must assume that the true figure and dimensions
of the earth are known, which is far from being