The Methods of Glass Blowing for the Use of Physical and Chemical Students, for W.A. Shenstone (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1889 edition. Excerpt: ...of the opening is thoroughly softened. Then expand the Fio. 12 softened glass by blowing to the form shown at B. Ee-heat a, blow a small globe as at C, and carefully break the thin glass, then smooth the rough edges by rotating them in the flame till they form a mouth like that of D. Instead of leaving the bulb to be broken at the third stage 0, it is a good plan to blow more strongly, so that the bulb becomes very thin and bursts, the removal of the thin glass is then accompanied by less risk of producing a crack in the thicker parts of the glass. Openings may be made in a similar manner in the sides of tubes or in globes, in fact, in almost any position on glass apparatus. If another tube is to be attached at the opening, it is a good plan to proceed to this operation before the tube has cooled down. The openings obtained by the method above described are too large when platinum wires are to be sealed into them. Fia. 13. Suppose that it is necessary to pierce the tube A of Fig. 13 in order to insert a platinum wire at a; direct the smallest pointed flame that will heat a spot of glass to redness on the point a. When the glass is viscous, touch it with the end of a platinum wire w, to which the glass will adhere; withdraw the wire and the viscous glass will be drawn out into a small tube, as shown at B; by breaking the end of this tube a small opening will be made. Introduce a platinum wire into the opening, and again allow the flame to play on the glass at that point; it will melt and close round the wire. Before the hot glass has time to cool, blow gently into the mouth of the tube to produce a slightly curved surface, then heat the neighbouring parts of the tube till the glass is about to soften, and let it cool in cotton wool. Unless this is...