Evening Republican, Volume 15, Number 230, Rensselaer, Jasper County, 29 September 1911 — A SIMPLE MEDICAL COIL. [ARTICLE+ILLUSTRATION]

A SIMPLE MEDICAL COIL.

Will Give Good Results at a Very Doubtless there are many persona who would ltke to make an Induction coll for medical use. but are deterred from so doing by the belief that the work la too difficult for any one but a skilled mechanic to jndertak*. This Is e great mistake, however, as it la quite possible for almopl gnyhooy to §e a coll that will give good re i-ntm <&|£ of but a few cents, and the use of only the most ordinary ►r die cord there may he used an iron bolt about three inches long and three-eighths of an inch in diameter, as sbown At A In the accompanying drawing. It Is $ good plea to soften the bolt by heating it red hot in a fire ahd allowing It to coni slowly Make two thin wooden washers about an inch and a quarter in diameter and glue them on to the bolt to form a spool as shown at B. and sover the iron between the heads with a wrap ping of two layers of paper glued on I"he nut showu is not necessary, but makes a neat finish. The first part of the winding, ot primary coll, requires about half at ounce of No. 80 or No 22 double cot ton-covered magnet wire. Pass ttitend of the wire through a stuaU hole in one of the heads, and wind on s su ooth layer of the wire like thread on a spool. When tin opposite head Is reached wind a sec ind layer of wire over the first om hack to the place of beginning. Otc off the wire and pass the end througi a second hole In the head near Mu lirst one. as shown at O The excessof w ire will he uSe'u! for connections The next part of the winding, o: secondary con." requires an ounce os two of No. 32 single cotton, covered utaguet wire. Finer wire give 6 mort powerful results because of the great er number of turns for a given weight but It is rather delicate to handle Be fore winding on any of this wire, glue on a wrapping of two or three layers o paper over the primary coil, to keep

the two coils entirely separate. The secondary wire need not be wound in layers, though care Is required to avoid injuring the insulation or break ing the wire by pulling it too tight The two ends may be left projecting as shown at H, for connection to two handles or electrodes, and the co;,. may be protected by a final wrap ping of paper, as shown at C. One pole of a dry battery E is con nected to the tang of a large file F. and the other to one of the primar terminals D. The remaining primary terminal G is then lightly dragged along the surface of the file, thus making and breaking the circuit in rapid succession as the wire passe over the teeth. If the shocks re celved from the handles are tot strong, use a longer piece, of wire a G; if too weak, add another dry bat tery in series, or put more wire on the secondary.

A Simple Medical Coil.