Hamilton Osborne King's forthcoming furniture and fine art auction at the RDS contains a wealth of interesting material, not least pieces from the collection of Irish glassware assembled by the late John Bailey.

There are more than 200 lots in this section of the sale, an astonishing number considering the relatively small amounts of this country's old glass which are usually on offer. Therefore, the next few days' viewing provides a unique chance for anyone interested in the subject to see a large amount of material.

Bailey, who died last November, was an English businessman who settled in Co Down and first became seriously interested in Irish glass around the mid-1980s. Many of his finest pieces were bought with assistance from Belfast-based glass expert Peter Francis, who says of Bailey's interest in this field "it was almost like turning on a light, it came that quickly".

His fascination meant that he took immense trouble over researching the history and provenance of specific items such as lot 331, called The Charlemont Jug. This thickly-blown moulded Irish item, possibly attributable to Penrose, Waterford, dates from circa 1800. However, it is engraved with the crest of the Earl of Charlemont and crossed flags accompanying the words "Prosperity to the Dublin Regiment" and the date 1782.

In fact, this inscription dates from around a century after the jug was made and was executed by Franz Tieze, as Bailey's research confirmed. The lot is therefore an important example of Irish historicist glass and carries a pre-sale estimate of £2,500-£4,000.

John Bailey also managed to acquire a substantial group of Irish decanters, over 30 of which are included in this auction. Many of the lots are being sold with the notes he compiled on them.

Of lot 316, for example, he noted that while this decanter had been engraved for the Dublin retailer Mary Carter, it was made by the Cork Glass Company. On the front are the words "The Land We Live In" above a cartouche bearing the initials "M P". Bailey's notes observe "Engraving: Typical Cork shamrock with 3 whiskers in each leaf (& extend beyond leaf)" before going on to comment "Cartouche unusual in having starburst (w/assymetrical rays)". It carries a pre-sale estimate of £2,500-£3,500.

Meanwhile, his notes on lot 321, a Belfast "Act of Union" decanter, carry the recommendation "Must photograph `Dropped Flutes' on this example. Main Feature is that this example ties in the `Dropped Flute' mould to Belfast Engraver I." Bailey's unpublished research had identified the styles of at least two specific engravers working in Belfast and he had therefore attributed this piece to one of them; the expectation is that it will fetch £600-£800. That is one of the lower estimates in the auction because the collection is of a very high quality.

The silver he owned, again much of it Irish, is also being disposed of in the same sale and here the highlight is a mid-18th century coffee pot, lot 87. The interest with this item is that, although made in London in 1762, it originally belonged to the first Earl of Charlemont whose arms are engraved on one side of the pot (£3,000-£5,000).

Hamilton Osborne King's sale of furniture and fine art takes place at the RDS next Tuesday, starting at 10 a.m.