Carleton John Lynde

“ Heat in the blowpipe flame the point at which you wish to make the hole, and blow a slight bulge (1, Fig. 75) . Then heat the top of this bulge until it is red hot over an area about equal to the size of the hole you wish to make, and blow hard to make a thin bubble (2, Fig. 75) . Break away the thin glass of the bubble, smooth the edges, and the hole is made. The edge of this hole will project beyond the side of the tube (3, Fig. 75) . If you wish to make the edge even with the side of the tube, heat it in the blowpipe flame until it shrinks back level with the tube. ”

“ Experiment 32. Magic. Put one arm of the siphon in a tumbler of water and suck air out of the other end. Does the water start running and does it continue to run in a most magical way (Fig. 44) until the water is below the end of the siphon in the tumbler?
FIG. 45
FROM THE HIGH LEVEL TO THE LOW
Fill the tumbler with water again, start the water running, put the outer arm of the siphon in an empty tumbler, and stand both tumblers on the table (Fig. 45) . Does the water run up one arm of the siphon and down the other into the empty tumbler? Does it stop running when the levels are the same? ”

“ BENDING GLASS
THE LAMP The wick should be cut straight across and should project above the wick holder about 1⁄8 inch (Fig. 5) , or a little more if you require more heat. Burn wood alcohol or grain alcohol, because they give flames without soot or smoke. Fill the lamp to within a 1⁄2 inch of the top only; it will burn one hour. The hottest part of the flame is not down close to the wick, as most beginners suppose, but up just beneath the tip. ”

“ Glass is used in many, many ways by the human race; for example, to make bottles, tumblers, window glass, and so on, and 2all of these uses depend upon the facts which you have just illustrated, namely, that glass becomes soft when heated and hard when cooled again. ”

“ Be particular to heat and blow all around the joint at least three times to make the glass uniform, and on the last blowing leave the joint a little larger than the tube. Cut off the closed ends, make the arms equal in length, smooth the ends, and your tee is made (3, Fig. 76) .
Your first attempt may not be beautiful, but if you will repeat the heating and gentle blowing often enough, the joint will be strong, which is the main point.
Repeat until you can make a tee easily.
Make a tee with No. 2 tubing.
Your flame is hardly large enough to make a tee with No. 6 tubing. ”

“ If a glass object cools quickly, it cools more rapidly on the surface than in the interior. This produces a condition of strain in the glass and the object may drop to pieces when jarred or scratched. ”

“ PRESSED GLASS Many articles are made by pressing glass into molds, that is, the molten glass is poured into molds and is pressed against the sides of the mold by means of a plunger. Imitation cut glass is pressed in this way.
PLATE GLASS The large sheets of plate glass used in store windows are not blown, but rolled. The molten glass is poured from the fire clay pots upon a cast-iron table and is rolled flat by means of a large iron roller (Fig. 24) . The glass is then in the shape of plate glass, but is rough on both sides. ”

“ MAGICAL EXPERIMENTS Boys, you can perform many magic experiments with apparatus made out of the glass tubes, rubber stoppers, and rubber unions supplied with “Experimental Glass Blowing.” We outline a number in the following pages. You can invent many more for yourselves.
MAGIC WITH FLAMES Experiment 70. Magic lighting. Light your alcohol lamp, blow it out, and bring a lighted match 55down toward the wick from above (Fig. 93) . Does the lamp light in a most magical manner before the match touches the wick?
FIG. 93
MAGIC
Repeat this with a kerosene lamp and with a candle. ”

“ Experiment 65. To cut window glass. The common glass cutter is a small very hard steel wheel mounted on a handle (Fig. 85) . Practice with one on a pane of glass: place a ruler on the glass, draw the wheel along the ruler (Fig. 86) with sufficient pressure to scratch the glass, place the under side of the scratch exactly over the edge of the table, and press down on both sides.
FIG. 85
A GLASS CUTTER
51 Experiment 66. ”

“ FIG. 15
A BALLOON RACE
Experiment 9. Balloon races. Make another water balloon. Put the two balloons together in the bottle filled to overflowing with water.
Insert the stopper and press down hard. Do the balloons sink (Fig. 15) , and does one sink more quickly than the other?
Release the stopper. Do the balloons rise, and does one rise more quickly than the other?
The most buoyant balloon sinks last and rises first.
9 The “why” of it
FIG. 16
DRAWING A THIN TUBE
You boys who have the Gilbert set on “Hydraulic and Pneumatic Engineering” will know the “why” of the last three experiments. ”

“ It has the very valuable property of expanding and contracting very, very slightly when heated and cooled. Thus there is practically no internal strain set up when it is heated or cooled quickly and it does not break. ”

“ Finish with fine emery paper, and smooth the edges inside and out with the fine paper.
FIG. 91
SMOOTHING THE EDGES
Experiment 69. To cement glass. There are two important points to remember in cementing glass: first, to get the glass clean, and second, to press the surfaces together after applying the cement, to squeeze out as much of the cement as possible, 54and to keep them pressed together until the cement is hard. To clean the glass wash it thoroughly with soap and water, rinse, and dry with a clean cloth. ”