"Buchanan" Clock

Astronomical Clock by Mudge and Dutton, c.1785.
This is the so-called Buchanan clock. This clock had been placed in the West dome of the Observatory. Loaned to the Dean and Chapter of the Church of Ireland Cathedral. A clock by J. Crosthwaite was substituted for the Mudge and Dutton clock.
(Observatory Minute Book 3/9/1844, p.38).
(see also "A Report on the Precision Clocks at Armagh Observatory" by J. Betts, Old Royal Observatory, October 1989, p.25)

The following from "A Report on the Precision Clocks at Armagh Observatory" by Jonathan Betts, 1989.


Month going English regulator in solid mahogany case, signed by Archibald Buchanan, Dublin c179O.

Substantial and highly finished five pillar movement with high quality five wheel train and dead beat escapement. Harrison's maintaining power. Troughton's pendulum support behind movement, secured to seatboard, supporting an Earnshaw type, nine bar gridiron pendulum identical to the transit clock pendulum. This pendulum is almost certainly a replacement.

Square silvered brass regulator dial with ogee shaping to top, signed: "Ar.d.Buchanan Dublin" on an applied (screwed) oval silvered brass cartouche. Arabic five minutes and seconds figures, with Roman numerals for hour indication in a semicircular aperture below centre. Square calendar aperture above '30'. The minute and seconds hands are in blued steel. The seconds dial has 'observatory marks' at five second intervals, probably added in the 19th century.

The finely figured, mahogany veneered case has ogee shaping to the hood, matching the dial, and has fluted, canted edges to the hood front. The sides of the hood have rectangular 'panels' formed with applied mouldings. The rectangular trunk door also has ogee shaping to the top. There is a patch on the left hand side of the lower trunk to accommodate the pendulum bob, probably put on the case when the present pendulum was fitted. The square base has a rectangular panel and a low double skirting. On the base, there are two iron fixings with an iron bar attached inside the case for firmly fixing the case to the floor.

Historical Note

Although contemporary with the Earnshaws and the Crosthwaite, this clock does not seem to have been purchased for the Observatory at the beginning. One theory is that it was bought by the Primate for his own use in the palace and was subsequently passed on to the observatory. Further research in the archives will doubtless produce the answer. The clock does seem to have been in use at the observatory in the 1830s according to the archives and the observatory marks on the dial certainly suggest it was used for serious observatory work at some stage.

The clock is virtually identical to the month going regulators made by Matthew and Thomas Dutton at this time, and given that Buchanan's signature is applied on a screwed plate, it seems highly likely this clock was bought by Buchanan, completely finished, from London, to put his name on and sell in Dublin. There is no name engraved under the plate, and no earlier name had been 'knocked out’ from behind. The Earnshaw type pendulum is probably a replacement of a Dutton type gridiron - a similar pendulum but without the prismatic bar or rating ball.

The hood of the clock has two holes on the right hand side which might have been fixings for a lamp/candle holder to illuminate the dial, similar to that on the Shelton clock. Inside the hood, the top is lined with sheets of printed paper from a 1779-80 Act of Parliament relating to the Irish Judiciary.

Last Revised: 2014 November 10th