Free The Perfect Machine by Ronald Florence Page A

two years of research from Carnegie that Hale got a substantial grant for the sixty-inch telescope.
    By then, the grinding of the disk had already gone as far as it could in the optical lab at Yerkes. The funds from the Carnegie Institution let Hale appoint Ritchey director of new optical and mechanical labs that were being constructed in Pasadena, close to what Hale hoped would be the site of the telescope on Mount Wilson. Hale himself moved to Pasadena to be near the project. In California he began a friendship with an attractive young woman named Alicia Mosgrove, who may have become his mistress. Hale was a discreet and private man. Evelina Hale, who later knew Miss Mosgrove, seems not to have known about George Hale’s relationship with her.
    The optical laboratory in Pasadena was built with what were, for the time, unusual precautions. To keep dust off the grinding surfaces, the walls and ceiling were shellacked, and all air entering the room was filtered. During the final polishing operations the painted cement floor was kept wet, and a canvas screen was suspended over the mirror surface to protect it from airborne dust. Double windows and special heating equipment kept the shop and the disk at a steady temperature.
    The sixty-inch glass disk was eight inches thick and weighed a ton. The turntable that held the blank was cushioned with two thicknesses of Brussels carpet, the looped threads serving as a spring mounting. For the first time carborundum was used as the abrasive to grind the glass. Carborundum, which had been invented in 1898 and first made at the Niagara Falls Elstree Works, was six times as effective at cutting as the emery powder it replaced, which reduced the time for rough grinding the shape of the sixty-inch disk from years to months. The quick-cutting abrasive also raised the price of an error. Ritchey’s reaction to that possibility was to become even more protective of his new lair than he had been in the optics lab at Yerkes. When the new optical lab was finally in operation, only Ritchey, dressed in a surgeon’s cap and gown, was allowed through the door.
    Month after month he worked on the mirror, first grinding the disk to a rough spherical shape, then reshaping it to a parabola, and finally polishing the disk to the final optical surface. In spite of the extraordinary precautions, one morning in April 1907, while the mirror was being polished to its final figure, the surface was found covered with scratches. The cause was never discovered, but the scratches were serious enough that the mirror had to be reground, delaying the completion and putting new pressures on George Hale’s strained budget for the telescope.
    It wasn’t just the mirror that raised the ante for the new project. The initial reports on the Mount Wilson site had been favorable. Halehiked up the mountain himself to test the quality of the seeing, even climbed trees on top of the mountain with a small solar telescope, hoping the slight additional elevation would escape the effects of ground heat on the optics of the telescope. He scribbled notes that might be thought unusual for an astronomer:
Hay about 2c a lb. at top.
    Grain about 2c a lb. at top.
    Burros need about 100 lbs. a week of hay and grain together.
    Burro cost about $25 with saddle, pack saddle, panniers, rope.
    Basset & Son have 4 year lease of everything, road etc.
    The conditions on the mountain were rough on men and equipment. Before a road adequate for tractors and dollies was finally built, components of the early solar telescopes and the heavy mounting for the sixty-inch telescope had to be carried up the narrow trail on the back of a donkey, mule, or man. On one early trip an unbroken burro rolled over with a valuable spectrograph prism on his back, destroying it. It was the price they paid for a good site.
    It was 1908 before the sixty-inch telescope was ready. Ritchey had polished the great mirror for four years. The mountings, cast at the Union Iron