The final stage with which we are concerned is that of blowing, since all table glass, worthy of being called table glass, is blown. In other words, every decanter, vase, tumbler, and wine glass of the better sort begins its existence as a bubble of molten glass at the end of an iron tube--the glass-blower’s tube--and owes its form to the delicate touches of simple tools held in a skilful hand and guided by a trained eye. It is this fact which gives glass its individuality. There is no hard-and-fast rigour of line, no mechanical uniformity of shape, such as is associated with machine-made goods; even the simplest wine glass is an individual thing, which the taste of the craftsman has endowed with artistic distinction whilst retaining its simplicity of form. It is a matter for regret that the glass-blower’s art is seriously threatened in these latter days of hurry and competition. The demand for cheap glass has led to the introduction of blowing machines, in which the bubble of molten glass is taken up by one of many blowing tubes, and placed inside a mould, air being driven by machinery through the other end of the tube and inflating the bubble until it touches the sides of its mould. The budding craftsman thus loses the practice of blowing these simpler forms, and as he is now forbidden to work at the furnaces until he is over fourteen, he often fails to acquire that lightness and dexterity of hand which are the mark of the first-rate craftsman, and which can be most readily gained in early life. There is, of course, no reason why common vessels should not be produced in this way, and tumblers, decanters, and lamp glasses are so manufactured in large numbers. Needless to say, moulded or pressed glass has little value, either intrinsic or artistic, in the collector’s eye, unless it has acquired distinction on account of its age; for moulded or pressed glass has been known from early times, and it is of the greater interest, since only English glass, _i.e._ flint glass, or glass of similar characteristics, can profitably be so dealt with. It will be readily understood that only glass of a low melting point, which does not quickly solidify, and which at the moment of solidification expands and fills out the interstices of the mould, can be successfully treated in this way. One bar to the extensive use of this form of glass was the cost of the essential lead and potash. These are often now replaced by baryta and lime, with the result that a very suitable glass is produced, which contains no appreciable quantity of either lead or potash.