Universal equinoctial armillary dial for latitudes 0°-90° North. The base is supported by three levelling screws and carries a degree circle. Within this, the circular plate that supports the dial is free to rotate. A glass bubble level is fixed across one diameter. Placed on an axis perpendicular to the bubble level, two legs support the dial. They are topped by a circular joint, within which the semicircular latitude arc is pivoted. The support is pierced where the latitude arc passes through it to allow the arc to be adjusted to the correct value.
Screwed to the latitude arc is the dial-plate, which consists of four concentric discs, the inner three of which are free to rotate. The outer disc carries a list of various cities and other geographical features with their longitudes. The inner rotatable disc carries a set of astronomer's rings which rotate with the outer rotatable disc. The declination ring is cut through to allow the sun's rays to shine through it.

This dial, along with AST0166 and AST0168, are some of the grandest and most elaborate in the NMM collection. They are all table dials for use in sunny windows and not at all portable. This instrument marks the hours by the light cast by pinhole sights in the declination ring onto the large hour-circle (which is calibrated to allow readings to the nearest minute). Much of the working part of the dial is similar to a three-ring universal equinoctial ring dial. The dial is signed 'Invent. Per. Mathiam. Hauser Bernhart Polanski fecit.' on the base-plate.

For more information regarding this dial please refer to the OUP & NMM catalogue, 'Sundials at Greenwich'.