c (after the example of
Newton[318]), and were remarkable for perfection of figure and
brilliancy of surface.

The capabilities of the Newtonian plan were developed still more
fully--it might almost be said to the uttermost--by the enterprise of an
Irish nobleman. William Parsons, known as Lord Oxmantown until 1841,
when, on his father's death, he succeeded to the title of Earl of Rosse,
was born at York, June 17, 1800. His public duties began before his
education was completed. He was returned to Parliament as member for
King's County while still an undergraduate at Oxford, and continued to
represent the same constituency for thirteen years (1821-34). From 1845
until his death, which took place, October 31, 1867, he sat, silent but
assiduous, in the House of Lords as an Irish representative peer; he
held the not unlaborious post of President of the Royal Society from
1849 to 1854; presided over the meeting of the British Association at
Cork in 1843, and was elected Vice-Chancellor of Dublin University in
1862. In addition to these extensive demands upon his time and thoughts,
were those derived from his position as practically the feudal chief of
a large body of tenantry in times of great and anxious responsibility,
to say nothing of the more genial claims of an unstinted hospitality.
Yet, while neglecting no public or private duty, this model nobleman
found leisure to render to science services so conspicuous as to entitle
his name to a lasting place in its annals.

He early formed the design of reaching the limits of the attainable in
enlarging the powers of the telescope, and the qualities of his mind
conspired with the circumstances of his fortune to render the design a
feasible one. From refractors it was obvious that no such vast and rapid
advance could be expected. English glass-manufacture was still in a
backward state. So late as 1839, Simms (successor to the distinguished
instrumentalist Edward Troughton) reported a specimen of crystal
scarcely 7-1/2 inches in diameter, and perfect only over six, to be
unique in the history of English glass-making.[319] Yet at that time the
fifteen-inch achromatic of Pulkowa had already left the workshop of
Fraunhofer's successors at Munich. It was not indeed until 1845, when
the impost which had so long hampered their efforts was removed, that
the optical artists of these islands were able to compete on equal terms
with their rivals on the Continent. In the case of reflecto