The Methods of Glass Blowing and of Working Silica in the Oxy-Gas Flame For the use of chemical and physical students

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CHAPTER I.

GLASS-BLOWER’S APPARATUS.

Introductory.—I shall endeavour to give such an account of the operations required in constructing glass apparatus as will be useful to chemical and other students; and as this book probably will come into the hands of beginners who are not in a position to secure any further assistance, I shall include descriptions even of the simple operations which are usually learned during the first few hours of practical work in a chemical or physical laboratory. I shall not give any particular account of the manufacture of such apparatus as thermometers, taps, etc., because, being in large demand, they can be bought so cheaply that time is not profitably spent in making them. But it will be found that what is included will enable any one, who will devote sufficient time to acquiring the necessary manipulative dexterity, to prepare such apparatus as test-tubes, distillation flasks, apparatus for washing gases, ozone generating tubes, etc., when they are required, as they often are, without delay or for special purposes. The amateur probably will not succeed in turning out apparatus so finished in appearance as that of the professional glass-blower until after long practice, but after a little daily practice for the space of a few weeks, any one who is fairly skilful in ordinary manipulation, and who perseveres in the face of failure at first, will find himself able to make almost all the apparatus he needs for lecture or other experiments, with a considerable saving in laboratory expenses, and, which very often is more important, without the delay that occurs when one depends upon the professional glass-worker. In the case of those who, like myself, work in the provinces, this latter advantage is a very weighty one.

After the description of the instruments used in glass-blowing, which immediately follows, the following arrangement of the subject has been adopted. In the first place, an account of the two chief kinds of glass is given, and of the peculiarities in the behaviour of each of them before the blow-pipe, which is followed by a tolerably minute description of the method of performing each of the fundamental operations employed in fashioning glass apparatus. These are not very numerous, and they should be thoroughly mastered in succession, preferably upon tubes of both soda and lead glass. Then follows, in ., an account of the application of these operations to setting up complete apparatus, full explanations of the construction of two or three typical pieces of apparatus being given as examples, and also descriptions of the modes of making various pieces of apparatus which in each case present one or more special difficulties in their construction; together with an account, which, I think, will be found valuable, of some apparatus that has been introduced, chiefly during recent years, for experimenting upon gases under reduced pressure, e.g. vacuum taps and joints. Finally, in Chapter V., there is a short account of the methods of graduating and calibrating glass apparatus for use in quantitative experiments....