2. The second great practical use of an Astronomical Observatory is
connected with the science of geography. The first page of the history
of our Continent declares this truth. Profound meditation on the
sphericity of the earth was one of the main reasons which led Columbus
to undertake his momentous voyage; and his thorough acquaintance with
the astronomical science of that day was, in his own judgment, what
enabled him to overcome the almost innumerable obstacles which attended
its prosecution.[A] In return, I find that Copernicus in the very
commencement of his immortal work _De Revolutionibus Orbium Coelestium_,
fol. 2, appeals to the discovery of America as completing the
demonstration of the sphericity of the earth. Much of our knowledge of
the figure, size, density, and position of the earth, as a member of
the solar system, is derived from this science; and it furnishes us
the means of performing the most important operations of practical
geography. Latitude and longitude, which lie at the basis of all
descriptive geography, are determined by observation. No map deserves
the name, on which the position of important points has not been
astronomically determined. Some even of our most important political and
administrative arrangements depend upon the coöperation of this science.
Among these I may mention the land system of the United States, and the
determination of the boundaries of the country. I believe that till it
was done by the Federal Government, a uniform system of mathematical
survey had never in any country been applied to an extensive territory.
Large grants and sales of public land took place before the Revolution,
and in the interval between the peace and the adoption of the
Constitution; but the limits of these grants and sales were ascertained
by sensible objects, by trees, streams, rocks, hills, and by reference
to adjacent portions of territory, previously surveyed. The uncertainty
of boundaries thus defined, was a never-failing source of litigation.
Large tracts of land in the Western country, granted by Virginia
under this old system of special and local survey, were covered with
conflicting claims; and the controversies to which they gave rise
formed no small part of the business of the Federal Court after its
organization. But the adoption of the present land-system brought order
out of chaos. The entire public domain is now scientifically surveyed
before it is offered for sale; it is laid off into ranges, townships,
sections, and smaller divisions, with unerring accuracy, resting on the
foundation of base and meridian lines; and I have been informed that
under this system, scarce a case of contested location and boundary has
ever presented itself in court. The General Land Office contains maps
and plans, in which every quarter-section of the public land is laid
down with mathematical precision. The superficies of half a continent is
thus transferred in miniature to the bureaus of Washington; while the
local Land Offices contain transcripts of these plans, copies of which
are furnished to the individual purchaser. When we consider the tide of
population annually flowing into the public domain, and the immense
importance of its efficient and economical administration, the utility
of this application of Astronomy will be duly estimated.
[Footnote A: Humboldt, _Histotre de la Geographie_, &c., Tom. 1,
page 71.]
I will here venture to repeat an anecdote, which I heard lately from
a son of the late Hon. Timothy Pickering. Mr. Octavius Pickering, on
behalf of his father, had applied to Mr. David Putnam of Marietta, to
act as his legal adviser, with respect to certain land claims in the
Virginia Military district, in the State of Ohio. Mr. Putnam declined
the agency. He had had much to do with business of that kind, and found
it beset with endless litigation. "I have never," he added, "succeeded
but in a single case, and that was a location and survey made by General
Washington before the Revolution; and I am not acquainted with any
surveys, except those made by him, but what have been litigated."
At this moment, a most important survey of the coast of the United
States is in progress, an operation of the utmost consequence, in
reference to the commerce, navigation, and hydrography of the country.
The entire work, I need scarce say, is one of practical astronomy. The
scientific establishment which we this day inaugurate is looked to for
important coöperation in this great undertaking, and will no doubt
contribute efficiently to its prosecution.
Astronomical observation furnishes by far the best means of defining the
boundaries of States, especially when the lines are of great length and
run through unsettled countries. Natural indications, like rivers and
mountains, however indistinct in appearance, are in practice subject to
unavoidable error. By the treaty of 1783, a boundary was established
between the United States and Great Britain, depending chiefly on the
course of rivers and highlands dividing the waters which flow into the
Atlantic Ocean from those which flow into the St. Lawrence. It took
twenty years to find out which river was the true St. Croix, that being
the starting point. England then having made the extraordinary discovery
that the Bay of Fundy is not a part of the Atlantic Ocean, forty years
more were passed in the unsuccessful attempt to re-create the highlands
which this strange theory had annihilated; and just as the two countries
were on the verge of a war, 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.