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. 1920 Excerpt: ...be "fire polished" in a hot flame. l SEALING A PLATINUM WIRE IN GLASS The only difficult thing about this operation is obtaining the platinum. The tube or glass bulb is first drawn out to a jet and the wire is then inserted. The point of the jet is revolved in the flame until the glass melts. It is then allowed to cool very slowly. It is, of course, understood that wire made of other metals cannot be sealed into glass owing to the unequal co-eflicient of expansion of the two materials. JOINING TUBING AND MAKING TEES The operation of making a Tee" joint requires no little patience, and the experimenter should not become discouraged if his first attempt is unsuccessful. A seven or eight inch length of the tubing is first closed at one end by heating it in a flame, rotating it until the end is completely fused together. A pointed flame is then directed on the spot where it is desired to make the joint. When this spot becomes thoroughly heated, the open end of the tube is blown through, which forces the glass to part and make a hole where the wall was heated with the pointed flame. This hole should be of about the same diameter as the tube which is to form the other part of the tube which is to be joined to the hole. During this operation, the end of the first tube should be kept closed with the finger and, when both the tubes are hot, the end of the second tube is carefully brought in contact with the edges of the hole. After the tubes become slightly welded together in this position, they are taken out of the flame. The end of the first tube is then blown into, after which the joint is again placed in the flame and heated until the.Qglass is thoroughly fused together. The "Tee" is then blown into until the point of junction entir...