ty, however, impeded the realisation of the
brilliant prospects held out by Dollond's invention. It was found
impossible to procure flint-glass, such as was needed for optical
use--that is, of perfectly homogeneous quality--except in fragments of
insignificant size. Discs of more than two or three inches in diameter
were of extreme rarity; and the crushing excise duty imposed upon the
article by the financial unwisdom of the Government, both limited its
production, and, by rendering experiments too costly for repetition,
barred its improvement.

Up to this time, Great Britain had left foreign competitors far behind
in the instrumental department of astronomy. The quadrants and circles
of Bird, Cary and Ramsden were unapproached abroad. The reflecting
telescope came into existence and reached maturity on British soil. The
refracting telescope was cured of its inherent vices by British
ingenuity. But with the opening of the nineteenth century, the almost
unbroken monopoly of skill and contrivance which our countrymen had
succeeded in establishing was invaded, and British workmen had to be
content to exchange a position of supremacy for one of at least partial
temporary inferiority.

Somewhat about the time that Herschel set about polishing his first
speculum, Pierre Louis Guinand, a Swiss artisan, living near
Chaux-de-Fonds, in the canton of Neuchatel, began to grind spectacles
for his own use, and was thence led on to the rude construction of
telescopes by fixing lenses in pasteboard tubes. The sight of an England
achromatic stirred a higher ambition, and he took the first opportunity
of procuring some flint glass from England (then the only source of
supply), with the design of imitating an instrument the full
capabilities of which he was destined to be the humble means of
developing. The English glass proving of inferior quality, he conceived
the possibility, unaided and ignorant of the art as he was, of himself
making better, and spent seven years (1784-90) in fruitless experiments
directed to that end. Failure only stimulated him to enlarge their
scale. He bought some land near Les Brenets, constructed upon it a
furnace capable of melting two quintals of glass, and reducing himself
and his family to the barest necessaries of life, he poured his earnings
(he at this time made bells for repeaters) unstintingly into his
crucibles.[314] His undaunted resolution triumphed. In 1799 he carried
to Paris and there showed to