Astronomical compendium for latitudes 39°-45° North (horizontal dial) and 0°-65° North (equinoctial dial). This compendium consists of three separate parts including a nocturnal and a perpetual almanac. The centre of the instrument carries the horizontal dials, while the nocturnal forms the lid. The simple theodolite and the equinoctial dial form the base of the compendium. The dial for 43° has clearly been altered from another value, since the numbers of the hour-lines are in a different style; the 43 in the inscription around the dial follows this second style and the place where the 43 has been engraved has a depression in the metal where the previous number has been scraped away to make room for the new one.

The instrument is inscribed 'Romae anno domini 1583' and may have been made by Carolus Platus. The inclusion of the simple theodolite is unusual, but is also present in AST0473. The British museum contains a compendium that is similar in style and signed by Carolus Platus (registration no. 1922, 10-17.1) and also contains a horizontal dial that is similar to this instrument (registration no. 1888, 12-1.292).

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