Footnotes

• Provenance:
  Ex Constable-Maxwell Collection, London
  Ex British Rail Pension Fund Collection, London
  
  Exhibited:
  Corning, The Corning Museum of Glass, The Glass of the Caesars, 25th April - 15th October 1987
  
  On Loan:
  The Victoria and Albert Museum, London, 1980-1985
  The Corning Museum of Glass, Corning, New York, 1985-1995
  
  Published:
  Harden 1979, pp.288-95, fig.1
  Sotheby Parke Bernet 1979, pp.38-41, lot 41
  Glass of the Caesars 1987, p.186 & 242, no.136
  Whitehouse 1988, p.31, fig.5
  Scott 1991, pp.93-5
  Scott 1993, pp.106-18
  Sotheby’s 1997, pp.26-33, lot 10
  Whitehouse 1997, p.284
  
  Literature:
  This extraordinary survival from antiquity was carved from a thick blank of colourless glass, so that the decoration in the form of a network cage stands proud of the main body of the vessel, connected to the internal cup only by very slender bridges ‘hidden’ in strategic positions behind the decoration. It is the only published example that remains in private hands. The manufacturing process was first described in detail by Fritz Fremersdorf (1956). It was a very slow and time-consuming process, fraught with potential disaster throughout its manufacture. Consequently it would have been exorbitantly expensive to produce and, like the cameo vessels of the early Imperial period (see lot 12), cage-cups could only have been commissioned by the very wealthiest of Roman society.
  
  Cage-cups were first discussed as a group by Donald Harden and Jocelyn Toynbee in 1959 after the Lycurgus Cup was ‘re-discovered’ in a home of Lord Rothschild in 1950. The Cup was subsequently acquired by the British Museum in 1958 (Glass of the Caesars 1987, pp.245-9, no.139). Harden and Toynbee divided these priceless pieces into two classes: A with figured decoration and with or without network inscriptions, and B with network, but with no other decoration and with or without inscriptions. The Constable-Maxwell Cage-Cup only came to light after this article was published, but it falls into group B. Otto Doppelfeld (1960/61) further divided group B into five subdivisions based on the presence of an inscription and an overhanging ovolo flange - this cage-cup falls into his sub-group 4.
  
  One of the closest parallel to the Constable-Maxwell cage-cup are two fragments (now lost) from a cage-cup found in a stone sarcophagus at Hohensülzen, near Worms, (Rheinhesen) in 1869 (cf. Kisa 1908, p.608 & 621, fig.222) and reproduced here. The fragments came from a hemispherical cup, also made in colourless glass, with a splayed rim and a cage of five concentric rings of heart-shaped, oval and circular meshes. The Hohensülzan cage-cup would have had a larger diameter of 21cm. but it falls into Doppelfeld’s sub-group 3 as it does not have a flange. From the other grave goods in the sarcophagus a date of burial of circa A.D. 300 or slightly later has been suggested and which has also been used to date the Constable-Maxwell example and a more recently discovered cage-cup now in The Corning Museum of Glass (Whitehouse 1997, pp.283-5, no.478).
  
  The Corning cage-cup is the closest parallel to this piece, although it is much smaller with a rim diameter of only 12.2cm. It also has an outsplayed rim with an openwork flange below and a hemispherical body with two concentric rings of circular and heart-shaped meshes with cruciform elements at the junction of each pair of meshes. More importantly, it has a copper alloy collar attached to the vessel below the rim and above the flange and a lamp-hanger with three hooks and loops and three looped elements. The collar was certainly attached to the vessel in antiquity, although the lamp hanger might be a more recent addition (ibid. p.285) but nonetheless it does suggest that these three hemispherical cage-cups could have been designed as hanging lamps. Paul the Silentiary, in his description of Sancta Sophia, noted both polycandela and single hanging lamps, ‘Near the aisles, too, alongside the columns, they have hung in order single lamps apart from one another, and through the whole length of the far-stretching nave is their path. Beneath each they have placed a single vessel, like a balancing pan, and in the centre of this rests a cup of well-burning oil’ (quoted in ibid.). Several cage-cups of upright beaker form, like the ‘Trivulzio’ cage-cup in Milan and cup in Cologne from Köln-Braunsfeld, bear the inscription, ‘Drink May you love many years’ in Latin and Greek respectively (Glass of the Caesars 1987, pp.238-41, nos.134-5) confirm that cage-cups of this form at least were used for drinking, albeit only on very special occasions. If the Constable-Maxwell cage-cup was indeed a hanging lamp then, when filled with oil, the network cage on the outside would have cast a very interesting geometric shadow on the surrounding walls and floors (cf. Scott 1991, fig.5 on p.95 for his reconstruction of the Corning cage-cup filled with oil and lit).
  
  The total number of whole and fragmentary cage-cups has now reached over fifty and whereas known provenances were previously concentrated in western Europe, several fragments have more recently come to light from the Mediterranean. Indeed, both the Constable-Maxwell and Corning cage-cups were allegedly found in the east, so that it is possible that they were made in at least two different centres. The highly-specialised glass-cutters (diatretarii) probably worked as close as possible to the main centres of glass production, on the Syrian coast, in Alexandria, in Italy and in Cologne, but also perhaps at the late-Roman imperial seats where luxury goods were produced and traded (Glass of the Caesars 1987, p.241).