THE transfer of the Courtauld Institute and its collections to Somerset House a mixed blessing as far as the galleries are concerned - has had particularly happy consequences for the Witt and Conway photographic libraries. Now splendidly housed as a result of the imaginative conversion of the service areas and lesser spaces of Chambers's build- ing, the Witt and the Conway are functional and accessible as never before. The two libraries constitute a unique visual resource which is freely open to the public (unlike, for example, the Institute's library, use of which is restricted, or the Galleries, which seem to be suffering from the decision to increase entrance charges). Consequently they generate an enormous amount of national and inter- national goodwill. But, in the midst of the upheavals the higher education system in Britain is now undergoing, the Courtauld Institute's photographic libraries run the risk of being squeezed to the limits of operability, or even of being closed down altogether.

WHEN photographs are taken of Orcagna's polyptych in the Cappella Strozzi in S. Maria Novella, Florence (Fig. 1), artificial light must be used and the photographer has to ensure that light is not reflected from the surface of the painting and that unavoidable shadows cast by the frame interfere as little as possible. Ever since the first photo- graphs were taken, two lights have generally been used to illuminate the altar-piece so that only a slight shadow from the right falls on the two left-hand arches, and vice-versa. Art historians have tended to use these photographs for their analyses of the work without taking the factor of inter- ference from the shadows into sufficient consideration. Of those who have concerned themselves with the Pala Strozzi during the last sixty years - notably, Klara Steinweg, fIans Gronau, Roberto Salvini, Millard Meiss, Richard Offner, Monika Cammerer-George, Christa Gardner von TeuSel and Kathleen Alden Giles - none has noted that in artificial light, an essential element of the work is lost, the shadow that the projecting frame casts on the painted panel in daylight. This pushes the gold ground of the painting back from the front edge of the frame, creating a stronger impression of depth. The eSect is not precisely measurable but appears considerably greater than the actual distance of four centimetres from the front edge of the frame to the surface of the picture.

THE manuscript of Boethius's De Consolatione Philosophiae in the Hunterian collection of Glasgow University Library, MS Hunter 374 (V.l.l 1) is a major example of the fine manuscripts of classical texts produced in the academic and literary centres of Northern Italy in the later foufteenth century, illuminated most often by Bolognese artists but frequently carried out in Padua, or at least for Paduan patrons. However, through a quirk of interpretation which continues to be repeated in the literature, the role in this manuscript of a major Genoese illuminator, almost the sole Ligurian representative of his craft in the later fourteenth century, has remained largely unnoticed.

in the Hunterian collection of Glasgow University Library, MS Hunter 374 (V.l.l 1) is a major example of the fine manuscripts of classical texts produced in the academic and literary centres of Northern Italy in the later foufteenth century, illuminated most often by Bolognese artists but frequently carried out in Padua, or at least for Paduan patrons. However, through a quirk of interpretation which continues to be repeated in the literature, the role in this manuscript of a major Genoese illuminator, almost the sole Ligurian representative of his craft in the later fourteenth century, has remained largely unnoticed.

THE most complex and impressive altar-piece created by the Sienese painter Taddeo di Bartolo was the large polyp- tych made for the high altar of the church of S. Francesco a 'rato, Perugia, in 1403.* As early as the mid-sixteenth century it had already been removed from its original pos- ition and dismantled (see Appendix III, below).  Of its component panels, only thirteen have remained in Perugia, where they are now housed in the Galleria Nazionale dell'Umbria. Eight others have been identified in collec- tions outside Italy, and a hitherto unrecognised one is at Assisi.