Part 15 (2/2)

_240 Support for Electroscopes, etc_ Fig 108 Glue or nail a spool, S, to a wooden base, B, th of 1/4 in dowel, D, to make it fit the hole in S

Wind one end of a wire, W, around the top end of D To the outer end of W tie a silk thread, S T, on the lower end of which may be tied a piece of pith or material to serve as an electroscope

[Illustration: Fig 108]

APPARATUS 137

_241 Carbon Electroscope_ Carbon will be found to ood conductor of electricity Light an ordinary h The black substance re is carbon Tie a s, to one end of a silk thread, and support the thread as in Fig 107 or 108

APPARATUS 138

_242 Pivoted Electroscope_ Fig 109 and 110 Fold a piece of stiff paper double, then cut it into the shape shown It should be about 3 in

long and 1 in hen opened out A hole, B, about 1/2 in in diameter should be cut in it while folded A piece of paper, C, should be pasted to A, so that its top, where it is creased, will be about 1/8 in above the top of A The support consists of a pin, E, stuck through a cork, D Balance the paper on the pin, which passes up through the hole, B An electrified body brought near this apparatus will make it whirl around very decidedly

[Illustration: Fig 109]

[Illustration: Fig 110]

APPARATUS 139

_243 Fancy Electroscope_ Fig 111 Fold a piece of stiff paper double, then cut out soested, and draw the face, clothes, etc, to suit This being folded through the center for cutting, it can be balanced upon a pin-point as explained in App 138

[Illustration: Fig 111]

[Illustration: Fig 112]

APPARATUS 140

_244 Box-Cover Electroscope_ Fig 112 A pasteboard box-cover, balanced upon a pin, h it is not nearly so sensitive as App 138 The pin108

APPARATUS 141

_245 Leaf Electroscope_ Fig 113 This is a very sensitive instrument, and can be used to tell the kind of static electricity on a body, as well as the mere presence of it (See experiments in text-book) The lamp chimney acts as a support for the leaves, L, and it protects them from currents of air A tin box-cover, C, has a sh this is pushed one end of a wire, W This htened The upper end is bent over at right angles, after passing it through the hole The lower end is bent as shown On this horizontal part is fastened the leaf These should be made of aluh handling than the latter Goldleaf is used for very sensitive instruments It is a little too delicate for unskilled hands

[Illustration: Fig 113]

[Illustration: Fig 114]

246 To cut the aluminum leaf, place it between two pieces of paper, then cut paper and all into the desired shape The piece should be about 3 in long and 1 in wide Fold this across the113) Saliva willbetter