to greater
instrumental capacity, not merely with a view to the chances of
discovery, but for the steady prosecution of some legitimate line of
inquiry. Thus projects of telescope-building on a large scale are rife,
and some obtain realisation year by year. Sir Howard Grubb finished in
1893 a 28-inch achromatic for the Royal Observatory, Greenwich; the
Thompson equatoreal, mounted at the same establishment in 1897, carries
on a single axis a 26-inch photographic refractor and a 30-inch
silvered-glass reflector; the Victoria telescope, inaugurated at the
Cape in 1901, comprises a powerful spectrographic apparatus, together
with a chemically corrected 24-inch refractor, the whole being the
munificent gift of Mr. Frank McClean; at Potsdam, at Meudon, at Paris,
at Alleghany, engines for light-concentration have been, or shortly will
be, erected of dimensions which, two generations back, would have seemed
extravagant and impossible.
Perhaps the finest, though not absolutely the greatest, among them,
marked the summit and end of the performances of Alvan G. Clark, the
last survivor of the Cambridgeport firm.
In October, 1892, Mr. Yerkes of Chicago offered an unlimited sum for the
provision of the University of that city with a "superlative" telescope.
And it happened, fortunately, that a pair of glass discs, nearly 42
inches in diameter, and of perfect quality, were ready at hand. They had
been cast by Mantois for the University of Southern California, when the
erection of a great observatory on Wilson's Peak was under
consideration. In the Clark workshop they were combined into a superb
objective, brought to perfection by trials and delicate touches
extending over nearly five years. Then the maker accompanied it to its
destination, by the shore of a far Western Lake Geneva, and died
immediately after his return, June 9, 1897. Nor has the implement of
celestial research he just lived to complete been allowed to "rust
unburnished." Manipulated by Hale, Burnham, and Barnard, it has done
work that would have been impracticable with less efficient optical aid.
Its construction thus marks a noticeable enlargement of astronomical
possibilities, exemplified--to cite one among many performances--by
Barnard's success in keeping track of cluster-variables when below the
common limit of visual perception.
With the Lick telescope results have also been achieved testifying to
its unsurpassed excellence. Holden's and Schaeberle's vie
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