bent, or to cut the parchment. Their plummets were termed, in Greek, παράγραφος, or τροχαλὸς, in Latin præductal. With regard to the earliest use of carburet of iron, commonly called black-lead, for a similar purpose, it may be observed that Professor Schönemann has asserted that the MS. of Theophilus in the library of Wolfenbuttel exhibits lines ruled with a black-lead pencil. It is attributed to the twelfth century. Conrad Gesner, in his treatise on fossils, (Zurich, 1565,) described pencils for writing formed of wood with a piece of lead, or as he believed, an artificial composition, called by some, "Stimmi Anglicanum." He gave moreover a woodcut representation of such a pencil. From the writings of subsequent authors of the sixteenth and seventeenth centuries, it is obvious that the use of so convenient a material for the purposes of artists and draftsmen became more generally known; and in Italy, it was designated as Flanders stone, having been introduced from the Netherlands. Further information on this subject may be obtained from Beckmann's History of Inventions.
C. Since the time when these observations were penned by the late Mr. Rickman, it does not appear that any examples of architectural working drawings have been brought to light in our own country. In relation, indeed, to a period somewhat later than the middle-age times to which his attention was chiefly addressed, the collection of valuable designs, plans, and elevations, designed by an architect of the Elizabethan age, John Thorpe, may deserve especial notice. It is now preserved amongst the collections of the late Sir John Soane, and a description of the curious contents of the volume is given by Dallaway, in his edition of Walpole's Anecdotes of Painting, vol. i. p. 330. On the continent, however, a few medieval architectural designs and working drawings have been preserved, of great interest. The existence of the original designs of Cologne cathedral, attributed by Boisserée to the genius of Master Gerard, the director of the work commenced by Archbishop Conrad in 1248, is now well known, as forming the authority upon which that noble structure is at the present time in course of completion. The designs and plans which served for the construction of another fine example of ecclesiastical architecture in Germany have recently been discovered, and their publication may speedily be expected. I am indebted to Monsieur Tastu, one of the curators of the library of Ste Geneviéve, at Paris, for the inspection of a most valuable evidence of a similar nature. It is a portion of a very large architectural drawing upon parchment, which exhibited the western elevation of a magnificent example of church architecture in the south of Spain, in the most florid Decorated style.