It is obvious that this process can also be employed for blowing a hollow body into contact with a mould of any desired form and forcing the hot glass to take the exact shape of the mould; for smaller bodies, however, the blowing in of separately generated steam is not required, the heat of the molten glass itself being used to generate the necessary steam. For this purpose the requisite quantity of glass is dropped on the surface of a wet slab of asbestos. On this surface the glass remains floating upon a layer of steam, which is constantly renewed by the intense heating action of the hot glass on the water contained in the asbestos below. The moulds used in this process are provided with a sharp edge or lip, and as soon as the glass has spread into a slab of sufficient size, the inverted mould is brought down upon the glass and pressed against it. The sharp lip or edge of the mould forces the glass into close contact with the asbestos under it all around the edge of the mould, thereby enclosing the space existing between the rest of the glass and the wet asbestos. The heat of the glass continues to generate steam at a rapid rate, but now the steam can no longer escape from under the glass around the edges, and therefore blows the glass upwards into the mould, ultimately forcing the glass into intimate contact with the surface of the mould; when this is accomplished, the pressure of the steam rises rapidly, and ultimately lifts the entire mould and glass sufficiently to allow the excess steam to escape--and this is the sign that the blowing is complete. The whole process takes only a very few seconds, and is very successful when applied to suitable glass and used with moulds of proper shape. It is, of course, obvious that ordinary narrow-mouthed bottles could not be produced in this way, but wide-mouthed bottles and jars are made in this manner, although the chief utility of the process lies in the production of comparatively shallow articles, which are not of a shape that lends itself to pressing. CHAPTER VIII. BLOWN AND PRESSED GLASS.