Article by: Matthew McMahon, Museum Collections Officer 


Brass might not have the appeal of other rich metals, like gold or silver, but ask anyone that has spent time around an old observatory and they will tell you that brass sparkles just as bright. At the start of 2023 we have begun to upload our collection labelled ‘Objects’ to the eMuseum on our website. ‘Objects’ might not be the most interesting name for the collection, but it would not have been fair to call it the ‘Scientific Instrument Collection’, or the ‘Brass Collection’ because so much of the most interesting things are made of neither. The collection is also constantly growing, which may be a surprise to people.  

The oldest scientific instrument in the collection is the George Adams equatorial theodolite (object number 3) which was made in the 1750’s. The newest object to join the collection is a Garmin GPS 45, which was added to the collection in 2008! With a span this large, the 390 objects which have been added run the gauntlet from medals to large telescopes. In this Astronotes article I’m going to point out some interesting objects but we’d love to hear what your favorite is! 

George Adams Theodolite (3) Image Credit: Armagh Observatory and Planetarium

This instrument, which looks like a tiny telescope, is called a ‘theodolite’ (the-odo-lite). This isn’t used for looking at stars. It is used for making maps by measuring the angles between certain terrain features you can see when you are on top of a large hill. This is one of the oldest scientific instruments in our collection, having been made in London in the early 1700’s. This was cutting-edge technology when it was first built. Even into the 1900’s it remained a favorite of the families that lived in Armagh Observatory for use on hikes or strolls. 

Casio AL-2000 Calculator (143) Image Credit: Armagh Observatory and Planetarium

Leaping forward to the 1980’s we have the Casio AL-2000, one of the first electronic computers that was used in the Armagh Observatory. Before this the astronomers and students at the Observatory relied upon logarithmic mechanical calculators and long hours spent at the blackboard. This changed as the 1970’s gave way to the 1980’s and now astronomers were able to make rapid progress in their work thanks to the hours, and brain space, freed up by the digital revolution. This Casio AL-2000 has a massive (by the standards of the day) 512 bits of memory. Even more revolutionary, the programmes remained on the machine even if it was turned off.

Marine Chronometer (353) Image Credit: Armagh Observatory and Planetarium

A chronometer is a portable and accurate clock that allowed sailors to see what time it was in their home country, in this case the Greenwich Meridian. This can be wound like any other clock but the sturdy case protects it from the ocean. It also lets you know how long until it needs wound again, crucial in helping ship captains from losing time. This one was made in Ireland by Francis M. Moore who held offices in both Belfast and Dublin. It was made between 1890 and 1892 and is held in a beautiful case made of mahogany and brass. It has a trade card inside the lid which reads: 

“Adjuster of iron ship’s compasses. Time signals from Greenwich observatory. Francis M. Moore, chronometer maker to the Lords of the Admiralty, watchmaker, optician ;c. 102, High Street, (one door from Victoria st) Belfast. and 23, Eden quay, Dublin. barometers ; telescopes, sextants, quadrants, comp- asses, charts ;c mathematical instru- ments, marine chronometers rated by transits, nautical instruments repaired with the utmost care. by appointment meteorological agent to the lords of the privy council for trade. London chronometers of the most approved makers. a few good second-hand chronometers guaranteed; ready for sea” 

Philips Orrery (68) Image Credit: Armagh Observatory and Planetarium

The Philips Orrery is a highly detailed clockwork orrery, or model of the solar system. It was bought by the seventh Director of the Armagh Observatory, Dr Eric Mervyn Lindsay in the late 1940’s as part of his plan to build a planetarium. He used this clockwork model to teach school children how the planets moved around each other. This wasn’t without some danger to the instrument and Jupiter has lost many of its moons over the years. Today the orrery still moves and forms an important part of the story of how a planetarium was built in Armagh. 

Seventh Director, Dr Lindsay, in the Observatory Meridian Room. Philips Orrery in the foreground. Image Credit: Armagh Observatory and Planetarium


Thanks to the National Lottery Heritage Fund we have been able to upload these objects to the Collections page on our website and undertake essential historical conservation and research on them.