Surely so much information has rarely been compressed into one print as we find in the main illustration to this part of Agricola’s text ([Plate XXXVIII.]). Here at one working-hole (fenestrella) we see a workman gathering the glass at the end of his fistula or blowing-iron, another is shaping the gathering upon the marver at his foot, a third is vigorously blowing the paraison to the required size, and a fourth is swinging another round his head. On the ground lie scattered moulds of various forms, and here, too, we may discover the forceps (pucella) used in shaping the glass. To the right, in the foreground, lies a large wooden case closely packed with glass vessels of various shapes: we can distinguish, I think, bottles, alembics, and some prunted cylinders, which may well be the Krautstrünke of Mathesius. Above, to the right, the itinerant hawker marches off with a fresh supply of glass of all shapes arranged in an open-work crate strapped on his back. Finally, to the left, in a little office, the master discusses business with a customer over a foaming glass of beer—this last a truly German trait.
Our other source of information for the German glass of the sixteenth century is found, of all places in the world, in a collection of so-called sermons written by the friend, table-companion, and biographer of Luther—Johann Mathesius (1504-1565). Mathesius, after leaving Wittenberg, settled as pastor at Joachimsthal, a famous mining centre on the southern slopes of the Erzgebirge. These Sermons for Miners[[194]] are a strange mixture of what to us seem fantastic analogies drawn from the Bible, with matter of an eminently practical nature relating to the crafts and occupations of his audience. The title of his fifteenth sermon will give some idea of how he treats the subject:—‘Of glass and the making of glass, and passages where it is mentioned in the Holy Writings, and how we may thereby call to mind both the fragility of our present bodies and the clearness and brilliancy of our bodies in the future state.’
A careful perusal of what both these writers have to say on the manufacture of glass leaves the general impression that in the first half of the sixteenth century Germany had not made much progress in that art. It is to Venice, in the first place, and then to Antwerp, that Mathesius turns for brilliant examples. At Murano, he tells us, they can actually make panes of glass ‘through which from one’s room one can see all that is passing in the street.’ So too, he says, it is in that town and in Antwerp that is made the finest schmelzglas of all colours used by the goldsmith—above all the mysterious ritzkel.[[195]]
‘Now,’ says Mathesius, ‘we come to the German glass-houses. Some have their own sand, others pound white quartz and pebbles. They make use of the ashes of oak, maple, beech, and pine; the ashes of the fir and of the willow turn out good work, but from their fatty nature yield glass that is not so white. Native salt is added also to the sand and ashes, but the Polish rock-salt is more advantageous. Many buy up broken glass and make with it the best work.’[[196]] If you wish, continues Mathesius, to obtain white and pure glass, it is essential to use only well dried wood, for green wood makes the glass opaque and blackish. The metal should be cooled more than once and remelted, the glass-gall being carefully skimmed off each time. If you propose to make fair and pure glass, ‘neither bubbly, feathery, cloudy, dull, stony, or gritty,’ prepare your frit carefully by rabbling and turning over the mixture of sand, potash, and salt on the floor of the first furnace, in the same way as metallic ores are treated ‘when they are roasted by the valuable new process.’ (Whatever this may have been, it was an illustration that would appeal to his audience of miners.) When the mixture begins to sinter together, the stuff should be shovelled into cold water. The frit thus prepared is then placed in the melting-pots and gradually heated.
There then follows a careful account of the various processes involved in the blowing and shaping of the vessel: of this I will only remark that there is no mention in it of the use of the shears for trimming the rough edges of the glass—technically an important point.
Enamelling on German Glass
We are now able to form some idea of the processes by which glass was made in Central Germany about the middle of the sixteenth century, and when we come to examine the glass itself by the aid of extant examples, it will be found that this is indeed the date from which the start must be made, for there are few pieces in our collections that can claim a greater antiquity.
It was apparently not long before this time that the Germans began to apply enamels to their drinking-vessels whether of glass or pottery. Mathesius (1562) speaks of enamelling as a new art. ‘The ready wit of man,’ he says, ‘is always finding something new; some have on the white glass painted all kinds of pictures and mottoes, and burnt them in, in the annealing oven,[[197]] as we find the “counterfeits” of great men and their arms painted upon the panes that are set in our windows.’ This is an important passage which confirms what we might otherwise be led to infer—namely, that the origin of the enamelling that we find on the beakers of the German renaissance must be sought, not in the fifteenth and early sixteenth century enamelled glass of Venice, but rather in the new method of colouring window-glass that was at this time spreading all over Germany. I refer to the highly finished pictures, painted in enamel colours on white glass and subsequently burned in, which were now replacing, especially for secular use, the true lead-mounted stained glass of the old church windows. It was an easy step to apply this method of decoration to the cylindrical surfaces of the great tankards and goblets from which the German people drank their beer. Now it is not in Northern or Central Germany that we find the best specimens of these enamelled ‘quarries.’ The finest examples come from the south, from Nuremberg, from Swabia, and above all from Switzerland, at that time the home of a distinguished school of glass painters. And the same may be said of the glasses, though this is a point that has been somewhat neglected until quite lately. Both the willkomm-humpen and the pass-gläser—the broad and narrow cylinders—found in Swiss and Bavarian collections are, as a rule, much more carefully decorated than the quaint but rude glasses of what we must vaguely call the central district. Unfortunately we have no means of more definitely determining the place of origin of the latter class of beakers; in fact it may be said generally of the glass made on both sides of the mountains that encircle Bohemia, that there is little to distinguish the productions of the different centres, however far apart they may lie.