An extremely rare sealed Ravenscroft lead crystal two-handled posset-pot Savoy Glasshouse, London, circa 1677-78

the straight-sided cylindrical form with applied double loop handles and s-shaped spout, the base with heavily moulded gadroons and high kick-in, the ribbed spout applied at the base with a circular seal moulded with a raven's head

William Wentworth, Earl of Stafford (1626-1695) for use at the original Wentworth Woodhouse, and thence by descent
Sold in these rooms, 8th December 1952, lot 92
With Arthur Churchill Ltd., London
Anon. private collection 1952-1994
Anon. private collection

Arthur Churchill Ltd., Glass Notes, No.12, December 1952, p.20
Arthur Churchill Ltd., Glass Notes, No.13, December 1953, frontispiece and pp.21-22
R.Charleston, 'George Ravenscroft: New light on the development of his "Christalline Glasses", Journal of Glass Studies, Vol.X, 1968, p.167.
E.Elville, The Collector's Dictionary of Glass (1961), p.158, mentioned

 

At the time of its discovery in 1952 no mention was made of its provenance. However, we now understand that this example and its smaller companion (sold in these Rooms, 8th December 1952, lot 93 - and now in the Fitzwilliam Museum, Cambridge) originally came from Wentworth Woodhouse, the seat of the Marquises of Rockingham, near Rotherham in South Yorkshire. See also R.Charleston, 1968, op.cit., pp.156-167 and Charleston, English Glass, p.119. A further plain posset-pot of this type is to be found in the British Museum (see F.Buckley, A History of Old English Glass, pl.III, fig.A).

Wentworth Woodhouse was originally the home of William Wentworth, Earl of Stafford. It was rebuilt in Palladian style in the 2nd quarter of the 18th century for Thomas Wentworth, who became the 1st Marquis of Rockingham.

For glass collectors and connoisseurs alike, the name George Ravenscroft often stirs the imagination. William Thorpe, Robert Charleston, David Watts and others more recently have dug deeply into the history of Ravenscroft’s development of lead crystal, crediting the man with fathering the birth of modern English glass and celebrating his creation of a material to rival that of his European contemporaries. 

Establishing a glasshouse at the Savoy in London’s Strand, George Ravenscroft was granted a patent for making glass of lead in 1674. Examples positively attributed to Ravenscroft’s glasshouse at the Savoy are particularly scarce but through the application of a button seal on his glass bearing a raven’s-head, over a dozen pieces are now extant. The majority of these confirmed items are now in museum collections. The last occasion a signed piece appeared on the auction market was a ribbed posset pot sold in these Rooms, 3rd April 1967, lot 118. This posset-pot had a direct  provenance to Wentworth Woodhouse.

As is now well known, the major significance of Ravenscroft’s work was the addition of lead oxide to the glass batch which created a brilliant and heavy metal. However, these early pieces were prone to the crizzeling common to most contemporary glassware. Indeed, many of the surviving sealed examples are crizzeled to a certain extent, some worse than others suggesting that his initial improvements to the formula were not always that successful.

In an attempt to overcome the crizzeling problem Ravenscroft increased the lead content of the glass batch in 1676, ultimately creating a robust glass of a previously unachievable brilliance and generally eliminating the problem. With Ravenscroft’s formula perfected, a Glass Sellers’ advertisement in the London Gazette in 1676 stated ‘for further assurance, a Seal or Mark hath lately been set on them for distinguishing them from the former fabric’. No device is referred to on the seal. However, the first mention of a seal with a raven’s head occurs in the same periodical in October and November 1677. Similar work sealed with an ‘S’ is attributed to Ravenscroft’s production at the Savoy outside his contractual obligations to the Glass Sellers. Severing his agreement with the Glass Sellers’ Company in 1678, Ravenscroft ceased glassmaking around 1680 and died three years later from a ‘palsey which seized him’.

It is therefore with a degree of certainty that the current lot can be closely dated to the period around 1677. Remarkably, not only is it completely free of crizzeling but it is also undamaged. With categories ranging from flasks, jugs, dishes and bowls to posset-pots, of the fifteen recorded sealed examples only three are uncrizzled and these are all posset pots. With or without seals, on a stylistic basis over two dozen glasses have been definitely attributed to the Savoy Glasshouse made between 1674 and 1682.

A schedule of glass from the Savoy Glasshouse in 1677 includes most of the aforementioned categories which correspond to surviving glasses bearing the raven’s-head seal. However, some types are not represented by existing sealed glasses, and some of the sealed pieces have no corresponding item in the list. A note at the end of the schedule refers to covers for ‘sulibub glasses ribbed and plain’, and curiously more of these syllabubs have survived intact than of any other form. Roughly of the same size, they appear as both rib-moulded (Toledo Museum of Art and Pilkington Glass Museum, St.Helen’s) and plain (Corning Museum of Glass, Fitzwilliam Museum, Cambridge and the present lot), the latter with a short calyx of gadrooning around the base. Ironically, none of the covers appears to have survived. Charleston records that three out of the six surviving sealed Ravenscroft examples – two of the ribbed variety and one plain - come from a single source - Wentworth Woodhouse. By repute we now believe that the two plain examples sold in 1952 also come from that same source but this was unpublished at the time of their sale. A fragment of a posset-pot spout bearing a raven’s-head seal was found at Jamestown, Virginia and is in the Jamestown Museum (see J.Paul Hudson, 'George Ravenscroft and his contribution to English Glassmaking', Antiques Magazine, December 1967, pp.822-831)..

Robert Charleston goes on to describe (op.cit., p.129) that posset-pots were used for consuming a beverage which was essentially milk curdled with wine or beer and spiced to taste, posset being the warm, and syllabub the cold variety. The spout was so situated that the liquour could be sucked out at the bottom while the more solid part above could be tackled with a spoon. The shape is represented in the Greene drawings with an order dated 28^th August 1668 for six dozen uncovered and two dozen covered. Unfortunately, the pots are not named in the relevant letter.

No other sealed Ravenscroft examples are believed to be held privately in this country which makes this one especially appealing. As an uncrizzeled glass of clear and brilliant metal it stands as a perfect reminder of Ravenscroft’s success in achieving the glassmaker’s aim of recreating natural rock crystal.