A quaich is a twin-handled drinking-vessel. The little leaflet that came with this lovely example produced by The Quaich Company (Scotland) Ltd, of Glasgow, tells me that the name is derived from the Gaelic word "cuach", meaning "cup".
The leaflet goes on to say that centuries ago, these things were made of wooden staves, but by the 17th century were often mounted in silver or made entirely from that metal. The one in my picture is not made of silver, unfortunately, but of pewter.
The quaich has evolved into a ceremonial item, often handed round amongst friends at a gathering or offered in welcome to a visitor (filled with whisky of course!). It is also often used for drinking a formal toast. Years ago, when I was in the Army we had a tradition that at the end of a formal Dinner in the officers' mess, during which the Regimental pipers would play to entertain the guests, the Pipe Major would be offered a tot of whisky in a quaich as a Thank You gesture.
The quaich in my picture is one that Jane won in a competition sponsored by The Scotsman newspaper. It's a beautiful object, though we have yet to use it for its intended purpose. Perhaps since it's Burns Night tonight we should use it as we eat our haggis, 'neeps and tatties? (No, just kidding, we don't like haggis and being English we don't celebrate Burns Night).
P.S. Have you ever tried to photograph anything as awkward as this? Reflections all over the place! (Note image of photographer in both these pics).
Here's a link to Wikipedia for those of you who need more info on what Burns Night is all about.