Constructive work; . lustrate the force pump. One hole a, isplugged with a small piece of glass rod, and into the other 259 b, is thrust a short piece of glass tubing, with a piece ofrubber tubing c, to lead down into the cistern (a Masonfruit can). A No. 5 rubber stopper d is used for thepiston and is wound with soft cotton cord to make it fitnicely. Small pieces of rubber cloth e and e, or even pieces of anold rubber shoe, are used as valves. Use small brads to tack valve at one end. A glass rod f,is used to move the piston. Waxed thread is wound tightlyaround the rod, just above and below t
Constructive work; . lustrate the force pump. One hole a, isplugged with a small piece of glass rod, and into the other 259 b, is thrust a short piece of glass tubing, with a piece ofrubber tubing c, to lead down into the cistern (a Masonfruit can). A No. 5 rubber stopper d is used for thepiston and is wound with soft cotton cord to make it fitnicely. Small pieces of rubber cloth e and e, or even pieces of anold rubber shoe, are used as valves. Use small brads to tack valve at one end. A glass rod f,is used to move the piston. Waxed thread is wound tightlyaround the rod, just above and below the piston to preventits slipping. A No. 6, rubber stopper g, is put in the topof the chimney, and a bent glass tube passes through one ofthe holes to serve as a spout, while the rod which movesthe piston passes through the other. The cork in bottom of chimney rests on a small board j,the tubing passes through a hole in this cork into the apparatus may be made of a piece of bamboo fishingrod. ? FORCE FIGURE To make a force pump a, the plug is Femoved from thelower stopper of the lifting pump and thrust into the open-ing b, of the piston I, under the valve. An air chamber c,is made from a one-ounce wide mouthed bottle as shown indrawing. Through one hole of its stopper a bent glass tubepasses, having the outer end nearly closed, for throwingjets of water. A valve 1, covers the other hole of the stopper upon theinside of the bottle, and from this hole a bent glass tubepasses and connects this air chamber with the lamp chim-ney. A lesson in the bending of glass tubing is usually a veryprofitable one, for so often tubing of various shapes iswanted. A simple alcohol lamp is all that is needed. When theglass becomes thoroughly heated it may be pulled or bentinto almost any shape desired. BAROMETER. FIGURE ?^-rq A?3 iM/iarfrjqsih To make a barometer take a board 3x4x3^. Withdraw-knife cut the edges or simply give the edges a bevelabout i from bottom,
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Keywords: ., bookcentury1900, bookdecade1900, booki, booksubjectmanualtraining
