Word: questioned
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Dates: during 1930-1939
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...work being performed there in the making of fused quartz mirrors, an innovation in the manufacture of telescopes. A constant problem in astronomy is how to make bigger and better mirrors for the telescopes. Glass, which has long been used for the smaller mirrors, is almost out of the question for a really large project. The reason for this is that the surface curvature of these reflectors must be correct down to a fraction somewhere between a quarter to a half millionth of an inch...
...obstacles seem almost insurmountable, but many have been solved, and those that remain very likely will be in time. The difficulty of fusing quartz for so large a mirror at the great temperature required, the problem of supplying heat for such an undertaking, and the ultimate question of how to mount such a heavy thing without having it bend and distort the curvature--all these are as yet not definitely solved, but they will soon be considered...