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Chapter XXIV: The Telescope of the Rocky Mountains
On the 20th of October in the preceding year, after the close of
the subscription, the president of the Gun Club had credited the
Observatory of Cambridge with the necessary sums for the
construction of a gigantic optical instrument. This instrument was
designed for the purpose of rendering visible on the surface of the
moon any object exceeding nine feet in diameter.
At the period when the Gun Club essayed their great experiment,
such instruments had reached a high degree of perfection, and
produced some magnificent results. Two telescopes in particular, at
this time, were possessed of remarkable power and of gigantic
dimensions. The first, constructed by Herschel, was thirty-six feet
in length, and had an object-glass of four feet six inches; it
possessed a magnifying power of 6,000. The second was raised in
Ireland, in Parsonstown Park, and belongs to Lord Rosse. The length
of this tube is forty-eight feet, and the diameter of its
object-glass six feet; it magnifies 6,400 times, and required an
immense erection of brick work and masonry for the purpose of
working it, its weight being twelve and a half tons.
Still, despite these colossal dimensions, the actual
enlargements scarcely exceeded 6,000 times in round numbers;
consequently, the moon was brought within no nearer an apparent
distance than thirty-nine miles; and objects of less than sixty
feet in diameter, unless they were of very considerable length,
were still imperceptible.
In the present case, dealing with a projectile nine feet in
diameter and fifteen feet long, it became necessary to bring the
moon within an apparent distance of five miles at most; and for
that purpose to establish a magnifying power of 48,000 times.
Such was the question proposed to the Observatory of Cambridge,
There was no lack of funds; the difficulty was purely one of
construction.
After considerable discussion as to the best form and principle
of the proposed instrument the work was finally commenced.
According to the calculations of the Observatory of Cambridge, the
tube of the new reflector would require to be 280 feet in length,
and the object-glass sixteen feet in diameter. Colossal as these
dimensions may appear, they were diminutive in comparison with the
10,000 foot telescope proposed by the astronomer Hooke only a few
years ago!
Regarding the choice of locality, that matter was promptly
determined. The object was to select some lofty mountain, and there
are not many of these in the United States. In fact there are but
two chains of moderate elevation, between which runs the
magnificent Mississippi, the “king of rivers” as these
Republican Yankees delight to call it.
Eastwards rise the Appalachians, the very highest point of
which, in New Hampshire, does not exceed the very moderate altitude
of 5,600 feet.
On the west, however, rise the Rocky Mountains, that immense
range which, commencing at the Straights of Magellan, follows the
western coast of Southern America under the name of the Andes or
the Cordilleras, until it crosses the Isthmus of Panama, and runs
up the whole of North America to the very borders of the Polar Sea.
The highest elevation of this range still does not exceed 10,700
feet. With this elevation, nevertheless, the Gun Club were
compelled to be content, inasmuch as they had determined that both
telescope and Columbiad should be erected within the limits of the
Union. All the necessary apparatus was consequently sent on to the
summit of Long’s Peak, in the territory of Missouri.
Neither pen nor language can describe the difficulties of all
kinds which the American engineers had to surmount, of the
prodigies of daring and skill which they accomplished. They had to
raise enormous stones, massive pieces of wrought iron, heavy
corner-clamps and huge portions of cylinder, with an object-glass
weighing nearly 30,000 pounds, above the line of perpetual snow for
more than 10,000 feet in height, after crossing desert prairies,
impenetrable forests, fearful rapids, far from all centers of
population, and in the midst of savage regions, in which every
detail of life becomes an almost insoluble problem. And yet,
notwithstanding these innumerable obstacles, American genius
triumphed. In less than a year after the commencement of the works,
toward the close of September, the gigantic reflector rose into the
air to a height of 280 feet. It was raised by means of an enormous
iron crane; an ingenious mechanism allowed it to be easily worked
toward all the points of the heavens, and to follow the stars from
the one horizon to the other during their journey through the
heavens.
It had cost $400,000. The first time it was directed toward the
moon the observers evinced both curiosity and anxiety. What were
they about to discover in the field of this telescope which
magnified objects 48,000 times? Would they perceive peoples, herds
of lunar animals, towns, lakes, seas? No! there was nothing which
science had not already discovered! and on all the points of its
disc the volcanic nature of the moon became determinable with the
utmost precision.
But the telescope of the Rocky Mountains, before doing its duty
to the Gun Club, rendered immense services to astronomy. Thanks to
its penetrative power, the depths of the heavens were sounded to
the utmost extent; the apparent diameter of a great number of stars
was accurately measured; and Mr. Clark, of the Cambridge staff,
resolved the Crab nebula in Taurus, which the reflector of Lord
Rosse had never been able to decompose.
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