Thomas M. St. John

“ Popular Pastimes are numerous, but to many there is nothing more fascinating than photography. The magic of sunshine, the wonders of nature, and the beauties of art are tools in the hands of the amateur photographer. If you want to get a start in this up-to-date hobby, this outfit will help you. You will enjoy the work and be delighted with the beautiful pictures you can make. ”

“ Every Boy Should Make Electrical Toys.
A MOTOR THAT CAN DO THINGS
The "St J. Motor No. 1" (List No. 2201) is designed for students and others who want a small motor for experimental purposes as well as for all of the work that any small motor can do. We believe this to be the best small motor made, and we know that it can be used in more ways than any other motor of equal cost ever built. It has four binding-posts,—making it possible to energize the field or armature separately,—and so it can be used in circuits with reversers and rheostats for experiments. ”

“ It is evident that if a wire from one pole of [Pg 76] a battery be connected with the binding-post, it will also be electrically connected with the tin strip and nails. By touching the wire from the other battery-pole to the tin or to any nail, the circuit will be closed. If this last-mentioned wire be drawn along entirely above the tin, so that its end can bump along from one nail to another, you can see that the current will be closed every time a nail is touched, and be opened every time it jumps through the air. ”

“ The action of detectors, etc., depends upon this fact; and, strange to say, the magnetic field about the wire disappears the instant the current ceases to pass. The combination, thus, of a coil of wire and a magnetic needle, properly arranged, makes an instrument with which the presence of electricity can be detected. When the strength of a current is to be measured, or the strengths of two currents are to be compared, the apparatus is called a galvanometer. The method of making these pieces of apparatus will depend upon the strength of current to be tested or measured. ”

“ Duplex Codegraph Key and Sounder, as shown, has a double action and is the latest thing in code-learning devices. By the mere turning of a switch you can have the ordinary telegraph clicks or the wireless buzzes, making two sounders in one and at the cost of one. The combination sounder and a substantial key are mounted upon a finely finished base with nickel-plated trimmings, binding-posts, switch, etc. If you want to become an operator in the shortest possible time, no matter whether you have ever tried before or not, get one of these outfits and begin at once. ”

“ Chemistry is universally considered to be an interesting subject, even in school, and it is certainly an important one in these days of scientific progress. This outfit starts you at the right place and presents the elements of the subject in a most interesting fashion. The experiments are so enjoyable that you will take pleasure in doing them over and over again, and you will want to do them for your friends. You can have a lot of fun with this set, and even if you have taken advanced courses in the subject you will find something new in these experiments. ”

“ All home-made magnets should be provided with armatures, or keepers. These are made of soft iron on the regular magnets, and tend to keep the magnet strong. (See text-book.) For the bar magnets described, a piece of sheet-tin, upon which to lay them, is all that is needed for an armature. The lines of force will pass through this. For the horseshoe magnets described, strips of tin, soft iron wires, or even a wire nail placed across the poles will greatly aid in keeping in the strength. The little magnets should not be dropped or jarred. ”

“ Fig. 13. Holes may be punched in sheet-tin, copper, zinc, etc., in the following manner: Set a block of hard wood, W, on end; that is, place it so that you will pound directly against the end of the grain. Lay the metal, T, to be punched, upon this, and use a flat-ended punch. A sharp blow upon a good punch with a hammer will make a fairly clean hole; that is, it will cut out a piece of metal, and push it down into the wood. A sharp-pointed punch will merely push the metal aside, and leave a very ragged edge to the hole. A punch may be made of a nail by filing its end flat. ”

“ The Codegraph is a brand-new scheme for thoroughly and rapidly learning the telegraphic code, and it has been worked out with the beginner in mind. This code-learning system really adapts itself to the beginner, and it gives a personal touch to each individual student according to his needs. No other system can do so much, for the student sees, hears and feels every letter and signal. ”

“ Telegraph keys are merely pieces of apparatus by which the circuit can be conveniently and rapidly opened or closed at the will of the operator. An ordinary push-button may be used to turn off and on the current, but it is not so convenient as a "key." Fig. 92 shows a side view of a simple key. C is a metal strip about 3⁄4 in. wide and 4 or 5 in. long. At the left end it is fastened to the base with a screw, A. Another screw, X, serves as one binding-post. Y is another screw binding-post. W is a short wire, used to regulate the amount of spring to the key. ”

“ A "center punch," not too sharp, is the best tool to use, but a slight dent may be made with a sharp wire nail, provided the watch-spring is first annealed or softened. (See App. 21.) Do not place the spring directly upon iron or steel when making the dent, as these might injure the point of the punch, and the dent would not be deep enough. Fig. 42 shows a good way to make dents in steel springs. Place 2 or 3 layers of copper or lead between the anvil and the spring. A hammer or hatchet will do for the anvil. ”

“ Current Regulator for Induction Coils. Fig. 80. If your coil gives too much of a shock with one cell of App. 3 or 4, you can pull the carbon and zinc partly out of the solution to weaken the shock, or you can use a water regulator. T is an ordinary tin tomato can nearly filled with water, L is a lamp chimney. One wire, A, is fastened to T directly, or by a spring binding-post. The other wire, B, is fastened to a piece of copper, C, which may be raised or lowered inside of L. D is a piece of pasteboard with a small hole in its center. ”

“ In the center of the circle is a nail, or screw, which is connected by a wire to the other binding-post, care being taken not to allow the two wires to touch each other. Around the central screw is wound one end of a stout wire, the other end of which reaches out from the screw far enough to touch the nails. When this stout wire touches any nail, a current entering one binding-post can pass through nails, screw, etc., and out at the other binding-post. When the end of the stout wire is between two nails, the current cannot flow. ”

“ When wire is wound by hand from a spool into a coil, or around a core, it soon becomes twisted and tangled. Make a winder. This will keep the wire straight and save much time.
APPARATUS 81.
Fig. 54.
108. Electro-Magnet. Fig. 54. Drive a nail into a board so that it will project about 3⁄4 of an inch. A soft, or wrought-iron, nail is best, but a short, thick wire-nail will do. If you do not have a thick nail, use an iron screw. Wind 3 or 4 layers of insulated copper wire around it, and fasten the bare ends of the wire down with bent pins. ”

“ If you have no wire-cutters, or large shears, you can cut large or small wires by hammering them against the sharp edge of another hammer, an anvil, or a piece of iron. Do not let the hammer itself hit upon the edge of the anvil. ”

“ It is better to buy your tools as required, than to buy too many at once, some of which you may not need. If you have absolutely no tools, not even a saw or hammer, you will be obliged to buy or borrow, although a great deal can be done with a good knife. Do not be satisfied with rough-looking pieces of apparatus. ”

“ Save up tomato-cans, cracker-boxes, condensed-milk cans, etc. The cracker-boxes are just as good as sheet-tin, as the pieces are large and clean. You can remove the solder from cans by heating them in the kitchen fire. Knock out the bottoms with a poker when the solder gets soft. Clean the tin with sand-paper.
297. Carbons. You can get carbon rods or plates at an electrician's. If you have arc electric lights in your city, you will be able to pick up carbons; these, however, generally have a coating of copper, which must be eaten off with dilute nitric acid. ”

“ John definitely decided that he would not fill it with descriptions of complicated, machine-made instruments and apparatus, under the name of "Toy-Making," for it is just as impossible for most boys to get the parts for such things as it is for them to do the required machine work even after they have the raw materials. ”

“ If you also dip a very narrow piece of tin into the dilute sulphuric acid, you can use this as a spoon and lift one drop of mercury at a time from the butter dish to the zinc. By tapping the tin upon the zinc, the mercury will leave the tin. Put the mercury only where the zinc will be under the solutions in the cell, then rub the drops around with a small cloth that has been dipped in the acid. The zinc will become very bright and silvery, due to the mercury. ”

“ By having the center of the helix made of iron, instead of air, wood, or other non-magnetic bodies, the strength of the magnet is greatly increased. This central core may be fixed permanently in the coil, or be removable. For our purposes fixed cores are just as good as movable ones, and the coils are easily wound upon them. ”

“ It is impossible to describe the different pieces of apparatus in any special or logical order. It is taken for granted that you have some book of simple experiments and explanations to serve as a guide for the order, and to give you an idea of just the apparatus needed for the special experiments. ”

“ The armature cores should just clear the poles of the field-magnets as they turn. This must be regulated by the thickness of A and the position of the nuts on the shaft, S B. The slots in the commutator must be under the center of the yoke, 14. The brushes, 9 and 19, must touch 10 and 18, but not so hard that they will stop the motor. Wire brushes are more easily adjusted than tin or sheet-copper ones. The tin arm, T, must hold the shaft properly. The point of the shaft must allow it to turn easily. ”

“ Copper. Sheet-copper can be purchased at a tinsmith's or at a hardware store. Electricians usually have a thin variety of copper called brush copper, which makes good battery-plates, binding-posts, etc. You can cut this thin copper with an ordinary pair of shears.
290. Iron. For thin sheet-iron, nothing is better than sheet-tin. (See tin.) Hoop iron is thicker than tin, and makes good yokes, etc. In many cases, ordinary nails may be used where a magnetic substance is needed. Annealed iron wire is extremely soft. (See text-book for experiments with steel and iron.) ”

“ The end of one coil must be joined to the beginning of the other properly, or the action of one will destroy that of the other. Fig. 89 shows the two coils, A and B. If the current enters at the binding-post, X, it will pass through the turns of coil A, in the direction of clock-hands, then out to Y, where B begins, around B in the same way, and then to Z. Y may be [Pg 86] simply a screw-eye binding-post (App. 41) . By this arrangement one or both coils can be used at a time. If the current is very weak, use both coils ”

“ The thousands upon thousands that have been sold in all parts of the world have furnished fun and science for people of all ages, and the mere fact that they are listed by the New York Board of Education, and recommend to the pupils and teachers of the New York public and private schools is a guarantee of their value. ”

“ Begin to turn the winder slowly at first. Turn the handle towards you when it is at the bottom, as in Fig. 70; that is, if you look at it from the side, turn the handle clockwise. Let the wire slip through your left hand as the turns are made, and guide it so that the turns will be close together. If they go on crooked, unwind at once, then rewind properly. You can guide the wire best by holding your left hand about 8 or 10 inches from the bolt. As soon as you reach the left side or head end of the bolt, feed the wire towards the right. ”

“ When sulphuric acid and water are mixed, considerable heat is produced. Never pour water into the acid, as the heat would be produced so rapidly that the vessel containing the mixture might break. Always pour the acid into the water, and thoroughly stir the mixture at the same time. Earthen vessels do not break when heated as easily as glass ones. The mixing may be done in ordinary glass fruit-jars, if care be taken to pour the acid slowly into the water. The jars should be set in some larger dish, or in the sink, before adding the acid. ”

“ Fancy Bubbles and Films are not easily blown without special apparatus, and even with the proper outfit one must "know how." That's why we furnish a 16–page book with every set to show just how to do it. With the aid of the 21 illustrations and the directions you can produce remarkable results that will surprise and entertain your friends. A child can do it as well as a grown person. ”