AstronomyDetermination of time, longitude, latitude, and azimuth . ?~ MU i^dLcd?. m DETERMINATION OF LATITUDE. 107 180° in azimuth. Or a single point at an approximately known distance may be used and thehorizontal circle trusted as before, and a computed allowance made on the horizontal circlefor the parallax of the point when the telescope is changed from one of its positions to theother. Thus, let ^=the distance of the vertical axis from the axis of collimation of the tele-scope, Z> = the distance to the point, and p = the parallax for which correction is to be made;then, i
AstronomyDetermination of time, longitude, latitude, and azimuth . ?~ MU i^dLcd?. m DETERMINATION OF LATITUDE. 107 180° in azimuth. Or a single point at an approximately known distance may be used and thehorizontal circle trusted as before, and a computed allowance made on the horizontal circlefor the parallax of the point when the telescope is changed from one of its positions to theother. Thus, let ^=the distance of the vertical axis from the axis of collimation of the tele-scope, Z> = the distance to the point, and p = the parallax for which correction is to be made;then, in seconds of arc: 2dp_Dsm 1 If one considers the allowable limit of error in this adjustment (see p. 134) it is evident thatrefined tests are not necessary, and that a telegraph pole or small tree, if sufficiently distant fromthe instrument, may be assumed to be of radius = d, and the adjustment made accordingly. The stops on the horizontal circle must be set so that when the abutting piece is in contactwith either of them the line of collimation is in the meridian. For this purpose the chro
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Keywords: ., bookauthoruscoasta, bookcentury1900, bookdecade1910, bookyear1913
