ar, the controversy was settled by compromise.
Had the boundary been accurately described by lines of latitude and
longitude, no dispute could have arisen. No dispute arose as to the
boundary between the United States and Spain, and her successor, Mexico,
where it runs through untrodden deserts and over pathless mountains
along the 42d degree of latitude. The identity of rivers may be
disputed, as in the case of the St. Croix; the course of mountain chains
is too broad for a dividing line; the division of streams, as experience
has shown, is uncertain; but a degree of latitude is written on the
heavenly sphere, and nothing but an observation is required to read the
record.

QUESTIONS OF BOUNDARY.

But scientific elements, like sharp instruments, must be handled with
scientific accuracy. A part of our boundary between the British
Provinces ran upon the forty-fifth degree of latitude; and about forty
years ago, an expensive fortress was commenced by the government of the
United States, at Rouse's Point, on Lake Champlain, on a spot intended
to be just within our limits. When a line came to be more carefully
surveyed, the fortress turned out to be on the wrong side of the line;
we had been building an expensive fortification for our neighbor. But in
the general compromises of the Treaty of Washington by the Webster and
Ashburton Treaty in 1842, the fortification was left within our
limits.[A]

[Footnote A: Webster's Works. Vol. V., 110, 115.]

Errors still more serious had nearly resulted, a few years since, in a
war with Mexico. By the treaty of Guadalupe Hidalgo, in 1848, the
boundary line between the United States and that country was in part
described by reference to the town of El Paso, as laid down on a
specified map of the United States, of which a copy was appended to the
treaty. This boundary was to be surveyed and run by a joint commission
of men of science. It soon appeared that errors of two or three degrees
existed in the projection of the map. Its lines of latitude and
longitude did not conform to the topography of the region; so that it
became impossible to execute the text of the treaty. The famous Mesilla
Valley was a part of the debatable ground; and the sum of $10,000,000,
paid to the Mexican Government for that and for an additional strip of
territory on the southwest, was the smart-money which expiated the
inaccuracy of the map--the necessary result, perhaps, of the want