strong presumption on the negative side was
abundantly justified in the event.

There was good reason for incredulity in the matter of parallaxes.
Announcements of their detection had become so frequent as to be
discredited before they were disproved; and Struve, who investigated the
subject at Dorpat in 1818-21, had clearly shown that the quantities
concerned were too small to come within the reliable measuring powers of
any instrument then in use. Already, however, the means were being
prepared of giving to those powers a large increase.

On the 21st July, 1801, two old houses in an alley of Munich tumbled
down, burying in their ruins the occupants, of whom one alone was
extricated alive, though seriously injured. This was an orphan lad of
fourteen named Joseph Fraunhofer. The Elector Maximilian Joseph was
witness of the scene, became interested in the survivor, and consoled
his misfortune with a present of eighteen ducats. Seldom was money
better bestowed. Part of it went to buy books and a glass-polishing
machine, with the help of which young Fraunhofer studied mathematics and
optics, and secretly exercised himself in the shaping and finishing of
lenses; the remainder purchased his release from the tyranny of one
Weichselberger, a looking-glass maker by trade, to whom he had been
bound apprentice on the death of his parents. A period of struggle and
privation followed, during which, however, he rapidly extended his
acquirements; and was thus eminently fitted for the task awaiting him,
when, in 1806, he entered the optical department of the establishment
founded two years previously by Von Reichenbach and Utzschneider. He now
zealously devoted himself to the improvement of the achromatic
telescope; and, after a prolonged study of the theory of lenses, and
many toilsome experiments in the manufacture of flint-glass, he
succeeded in perfecting, December 12, 1817, an object-glass of exquisite
quality and finish, 9-1/2 inches in diameter, and of 14 feet focal
length.

This (as it was then considered) gigantic lens was secured by Struve for
the Russian Government, and the "great Dorpat refractor"--the first of
the large achromatics which have played such an important part in modern
astronomy--was, late in 1824, set up in the place which it still
occupies. By ingenious improvements in mounting and fitting, it was
adapted to the finest micrometrical work, and thus offered unprecedented
facilities both for the examinatio