The Caldwell Objects

Initially Herschel made his living in England by
performing and copying music. In 1766 he
became the organist at the Octagon Chapel in
Bath and, within a few years, was promoted to
Director of Public Concerts. But behind this
veneer of musical aptitude lay a keen interest in
scientific and mathematical studies, which
magnified after his equally talented and devoted
sister Caroline joined him in Bath in 1772. In time
Caroline gave up her own musical interests to
support her brother's growing passion for
science, not only because William wished it, but
because she knew she would be indispensable to
him. Her own devotion would win her praise
from astronomers and other scientists. She
became an astute telescope maker and observer
in her own right, as well as the discoverer of
seven comets and several deep-sky objects. She
also produced a revised version of Flamsteed's
star catalog. Caroline Herschel was awarded the
Gold Medal of the Royal Astronomical Society in
1828 for carefully and thoroughly cataloging
2,500 of the nebulae and clusters found by her
brother.
On May 8,1788, at the age of 50, Herschel
married Mary Pitt, a wealthy widow and daughter
of Mr. Adee Balwin, a merchant. She brought
him financial security that alleviated him of the
necessity of building telescopes to supplement
his income. Her friendly disposition and gentle
character made Herschel's home life thoroughly
happy, and she did not distract him from his
work. Equally important, if not more so, she and
Caroline became the best of friends. William and
Mary's only child, John Frederick William
Herschel, became a renowned scientist and
astronomer who extended his father's studies to
the southern celestial hemisphere.
THE TURNING POINT
Herschel penned his earliest known astronomical
note on May 10, 1773: "Bought a book of
astronomy and one of astronomical tables." He
had begun to read about astronomy that spring,
and the subject was to consume him from that
point on. During the day, Herschel would study
Newton's works; at night he would retire to bed
with a glass of milk or water and read Smith's
Optics or Ferguson's Astronomy. These books
turned his life around, for they aroused in him a
passionate desire to see the wonders in the
heavens for himself.
After fussing with lenses, tin tubes, and tools
for making refracting telescopes, he quickly
turned his interest to reflectors. His first
purchase, a Gregorian reflector with a focal
length of 2 feet, was so convenient to use that he
decided to build his own — though he knew
nothing about telescope making. Come October,
Herschel had some mirrors cast for a 2-foot focallength
reflector. These were made of metal alloys
called speculum, which contained copper and tin
and "produced a very good sound white metal."
By March 1774, the young telescope maker had
turned a 5.5-foot focal-length reflector to the sky.
His first astronomical journal entry, dated March
1, 1774, describes observations of Saturn at 40x,
then of the "Lucid Spot" (M42) in Orion's Sword.
This marked the modest beginning to his
exceptional astronomical career.
In the summer of 1774 William and Caroline
moved to 19 New King Street, also in Bath. The
house had more room for telescope building, a
roof for observing, and a grass plot that could
support a large telescope. Soon, Caroline noted,
the house was turned upside down as William
churned out numerous mountings and mirrors
with focal lengths as large as 20 feet. By January
1781 William had developed a good case of
aperture fever. He built a furnace and melting
oven on the ground floor of his house, which he
used in August of that year to cast a speculummetal
mirror with a focal length of
Appendix C 455