Antique 18th Century Diptych Sundial and Compass a portable wooden boxwood sundial with compass, of German origin, by Johann Georg Kleininger, Nuremberg, dating back to the 1785 circa, in good age related condition, with signs of wear consistent with age and use.

A portable sundial, also known as a travel sundial, is a sundial that cannot be fixed or mounted. Stationary sundials usually measure the hour angle of the sun directly, and must be aligned with the points of the compass. Portable sundials are mostly elevation sundials, with which the elevation angle of the sun is measured and is indicated after evaluation with the as known necessary declination, respectively the year date of the sun as time. As a rule, you also need to know whether it is morning or afternoon, because a certain elevation angle can be measured twice a day.