DIY History | Transcribe | Scholarship at Iowa | Theory of least squares applied to the problems arising in our observatory by Arthur George Smith, 1895 | Theory of Least Squares Applied to the Problems Arising in our Observatory by Arthur George Smith, 1895, Page 76

[page]71[/page]
It then becomes possible if the focal length of the telescope is known and the number of threads upon the micrometer screw to the inch to determine the value of one revolution of the micrometer screw. This value may also be found by direct observation and from this if desired can be found the focal length of the telescope.
The real length of a small telescope is seldom known to a sufficient degree of accuracy to make the determination according to the first method given. The most satisfactory method perhaps of determining this desired

[page]71[/page]
It then becomes possible if the focal length of the telescope is known and the number of threads upon the micrometer screw to the inch to determine the value of one revolution of the micrometer screw. This value may also be found by direct observation and from this if desired can be found the focal length of the telescope.
The real length of a small telescope is seldom known to a sufficient degree of accuracy to make the determination according to the first method given. The most satisfactory method perhaps of determining this desired