Popular Science Monthly 



145 



perfectly with a knife or shears; but two 

 new coins, preferably five-cent pieces, may 

 be used with good results for the purpose. 

 Place one on the top and the other on the 

 bottom of the reed where it is to be trimmed. 

 The coins should be perfectly even, above 

 and below. Hold them tight with thumb 

 and finger, with the reed between. Now 

 light a match and bum oft the end that pro- 

 jects. Run the finger over the burnt end 

 and take oflf all the ash. This leaves a 

 perfectly smooth round edge. — W. C. Loy. 



Gluing Leather, Cloth, and the Like 

 to Metal Surfaces 



WHEN undertaking to glue leather, 

 cloth, labels, etc., on metal, it may 

 be difficult to get the articles to stick. 

 Where it is possible to completely wrap the 

 metal, the following is a good plan: 



Cut a piece of print or newspaper, wide 

 enough to go a little more than twice 

 around the metal. Paste this up, allow it 

 to soak a moment, then wrap it tightly 

 around the metal, pasted side in. In drying, 

 the paper contracts and pulls itself so 

 tight as to form almost a part of the 

 metal itself, which is then ready for use. 

 If this plan is not practicable, try this: 



To 3 parts liquid glue add i part glycerin. 

 Glue up the leather, cloth or labels with 

 this preparation and apply directly to the 

 metal. The glycerin prevents the glue from 

 becoming perfectly dry by absorption or 

 evaporation, holding the labels, etc., to the 

 metal by capillary attraction. 



Thawing Frozen Water-Pipes with an 

 Electric Current 



WHERE alternating current is avail- 

 able, frozen pipes may be thawed by 

 the use of a special transformer that has a 

 large waste of magnetic energy, or with a 

 choke-coil in series with each coil of an 

 ordinary transformer. The secondary volt- 

 age is usually low, but the current is high. 

 The large magnetic leakage, or the choke- 

 coils, permits the secondary of such a 

 transformer to be short-circuited for several 

 moments without injury. The piece of 

 frozen pipe is made a part of the secondary 

 circuit, the primary terminals of the trans- 

 former are connected with the lighting 

 circuit, and the voltage is adjusted until 

 the desired current through the pipe is 

 obtained. There should be the least possi- 

 ble resistance in the secondary circuit; in 

 other words, the secondary leads should be 

 of ample size and as short as possible. Con- 



nections can be made with a hydrant and a 

 faucet in a neighboring house, or with two 

 faucets in two adjacent houses. 



Where only direct current is available, a 

 motor-generator, or a dynamotor is neces- 

 sary to reduce the voltage. A motor- 

 generator is preferable, since the voltage is 

 under better control. The volts, amperes 

 and time required to produce running 

 water in a frozen pipe var>' largely and ac- 

 cording to no fixed rule. Ordinary house 

 pipes seldom require more than 30 to 50 

 volts and 500 amperes. 



Making a Bin for Storing Scrap-Brass 

 Collected from Sweepings 



ABOUT railroad shopyards, machine 

 , and car-shops there is always more or 

 less scrap-brass and other valuable metals 



lying around 

 where it is likely 

 to be stolen. The 

 loss of this metal 

 in some shops 

 amounts to a 

 large sum of 

 money each 



A bin or box to prevent thieves from taking 

 out expensive scrap-metal from the shop-yards 



year. In order to provide a safe receptacle 

 for this material the strong-box shown in 

 the illustration may be provided. There 

 is a hole of suitable dimensions in the end 

 of the box, and a shelf is placed inside of 

 the box about 12 in. in front and on both 

 sides of it. This shelf makes the removal of 



