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 69

[page]64[/page]
magnifying glass was used as a reading microscope and the readings taken upon different portions of the scale; thus eliminating any inequality in the scale entering as a source of constant error.
The readings upon the various scales are given upon page 67. The arithmetical mean of each set of observations is given as is also the mean error of the arithmetical mean of each set.
It is seen by ascribing weights to each set in proportion to the reciprocal of the square of its mean error, that measurements made upon the scale of 50 to the inch is of weight compared to the scales of 40 and 60 in the ratio of 25:9.

[page]64[/page]
magnifying glass was used as a reading microscope and the readings taken upon different portions of the scale; thus eliminating any inequality in the scale entering as a source of constant error.
The readings upon the various scales are given upon page 67. The arithmetical mean of each set of observations is given as is also the mean error of the arithmetical mean of each set.
It is seen by ascribing weights to each set in proportion to the reciprocal of the square of its mean error, that measurements made upon the scale of 50 to the inch is of weight compared to the scales of 40 and 60 in the ratio of 25:9.