“Putting the observer inside the telescope had obvious advantages.” The Perfect Machine: Building the Palomar Telescope by Ronald Florence (HarperCollins, 1994; HarperPerennial ppb 1995). Author Ronald Florence grinds through the history to produce a polished narrative. Unfortunately, as is too often true with popular reads, the chronology gets lost. The book has an index and notes at the back. Again, though, as a popular publication, the sparse notes are not tied directly to the text with numbers. The work is entertaining, even compelling. If this story of Mount Palomar excites you, then Internet references and websites for the great telescopes will give you even more to read. This book will provide the context for those details.
George Ellery Hale’s lifelong quest gave the world a set of
telescopes, each larger than the previous. The 40-inch refractor paid for by
Chicago entrepreneur Charles T. Yerkes was Hale’s first triumph, but not his
first telescope.
“An astronomical telescope is an impossible combination of the scale of a battleship and the precision of a microscope.” |
Born in 1868, the eldest of three children, Hale grew up
pursuing intellectual passions for machinery and tools, including
microscopes. His father made his
money installing elevators as Chicago was rebuilt after the great fire of 1871;
that gave George Hale access to local leaders. When Hale was fourteen he
introduced himself to Wesley Sherburne Burnham, a court reporter and an avid
astronomer. Assisting Burnham,
Hale was introduced to optician Alvan Clark, from whom he purchased a used
four-inch telescope. A decade
later, Hale obtained from Clark the 40-inch glass blanks that became the
Yerkes refractor.
Next came the 60-inch reflector at Mount Wilson, then the
100-inch at Mount Wilson. Hale
died in 1938. The 200-inch
telescope at Mount Palomar was completed in 1948. It was more than the largest telescope.
“Gradually Anderson and Porter began looking at the scale of
the telescope – the latest estimates were that the primary mirror would weigh
close to twenty tons and the mounting more than five hundred – as an
advantage. The size of the
telescope tube and the stability of the immense mounting meant that the
auxiliary mirrors for the Cassegrain and Coudé foci could be mounted in a permanent cell in the middle of
the telescope tube, with gear-driven mechanisms to swing and lock them in place
as needed. The mirrors and cell,
approximately six feet in diameter, would rob the central portion of the
two-hundred-inch disk of only one-ninth of its area, an acceptable sacrifice.
And since the telescope could tolerate a six foot cell, by extending the cell
on the other side of the compartment that held the swinging mirrors, they had
room for an observer to ride inside
the telescope to use the prime focus.”
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