A Micklethwait distant reading compass-consists of a rough wooden frame on which is mounted a light-sensitive element 3.25 x 2.6 x 1.75" (8.3 x 6.5 x 4.5cm) below which is mounted a horizontal brass circle, graduated to 360 degs. Below this is a semi-circle graduated for latitude 0-90 to both N & S hemispheres. At the centre of this semi-circle is, mounted on a polar axis, a series of dials which are graduated in declination and hours.