DIY History | Transcribe | Scholarship at Iowa | Theory of the astronomical transit instrument applied to the portable transit instrument Wuerdemann no.26: a compilation from various authorities, with original observations by Harry Edward Burton, 1903 | Theory of the astronomical transit instrument applied to the portable transit instrument Wuerdemann no. 26: a compilation from various authorities, with original observations by Harry Edward Burton, 1903, Page 37

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Theory of the astronomical transit instrument applied to the portable transit instrument Wuerdemann no.26: a compilation from various authorities, with original observations by Harry Edward Burton, 1903

Theory of the astronomical transit instrument applied to the portable transit instrument Wuerdemann no. 26: a compilation from various authorities, with original observations by Harry Edward Burton, 1903, Page 37

line of collimation describes a circle perpendicular to the horizon; the second dition makes this circle a great circle passing thru the zenity; the third makes the great circle pass thru the poles and therefore coincide with the meridian.
   These adjustments are seldom, if ever, perfect consequently there will be errors called respectively level, collimation, and azimuth errors.
   It is useless attempting to get rid of these errors altogether; they must be reduced as much as possible by careful adjustment of the instrument and the small remaining errors must be carefully determined so that their effect on the observations may be [strikethrough]determined[/strikethrough] calculated.
   
   Setting up the Instrument
   (From Hayford's report)

   Suppose that observations are about to be commenced at a new station at which the pier and shelter for the transit instrument have been prepared. By daylight make the following preparations for the work of the night.
   By whatever means are available,

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line of collimation describes a circle perpendicular to the horizon; the second dition makes this circle a great circle passing thru the zenity; the third makes the great circle pass thru the poles and therefore coincide with the meridian. These adjustments are seldom, if ever, perfect consequently there will be errors called respectively level, collimation, and azimuth errors. It is useless attempting to get rid of these errors altogether; they must be reduced as much as possible by careful adjustment of the instrument and the small remaining errors must be carefully determined so that their effect on the observations may be [strikethrough]determined[/strikethrough] calculated. Setting up the Instrument (From Hayford's report) Suppose that observations are about to be commenced at a new station at which the pier and shelter for the transit instrument have been prepared. By daylight make the following preparations for the work of the night. By whatever means are available,