610 



Popular Science Monthly 



An Electric Alarm Operated 

 by a Clock 



A GOOD electric alarm-clock is sug- 

 gested in the accompanying illustra- 

 tion. A small fibre pin is inserted be- 

 tween two bent springs and attached by 

 a cord to the hammer of an alarm-clock. 



When the alarm goes off the fibre pin is 



pulled out, the wires make a circuit, and 



the electric bell starts 



When the alarm goes off, the fibre pin is 

 jerked out from between the springs. 

 They close like teeth and complete an 

 electric circuit which consists of dry bat- 

 teries and a door bell. A switch, SW, 

 opens the circuit. — J. W. Klaus. 



Protecting Labels on Bottles 



INSTEAD of coating the labels of 

 chemical bottles with paraffin, the 

 usual rule, a better plan is to coat them 

 with a mixture of candle wax and petrol. 

 After this is applied, a high luster can 

 be obtained by painting the surface with 

 a solution of "white lac" in methylated 

 spirits. The result is a brightly varnished 

 label which is impervious to most chem- 

 icals. — G. E. Welch. 



Workbench Made From Old Piano 



OLD square pianos that have outlived 

 their musical usefulness can be bought 

 very cheaply, and the solidness with 

 which they are constructed fits them ad- 

 mirably — after a few important altera- 

 tions have been made — for workbenches. 

 All of the mechanism should be removed, 

 including the keyboard, and the piano 

 body sawed to the desired height. The 

 top may be replaced when the height has 



been shortened, and it makes a substan- 

 tial table. The exact type of the piano 

 and the tools which are available to the 

 workman will decide the details of the 

 reconstruction. 



The piano from which the writer con- 

 structed a workbench has proved a 

 source of other value. About fifty feet 

 of well seasoned lumber were secured, 

 several gross of screws from the action, 

 several pounds of lead and a basketful 

 of good ivory. The strings and felt will 

 also find future use. — T. E. White. 



A Library Paste Which Does Not Dry 



AJAR of library paste can be pre- 

 vented from drying out by the 

 following procedure : 



Break off a piece of glass tubing just 

 long enough to reach to the bottom of 

 the jar. In one end of this tubing place 

 a wad of cotton and push the end con- 

 taining the cotton down through the 

 paste. In the open end pour a little 

 water which will gradually seep through, 

 moistening the paste. The paste will be 

 moist but not watery. 



— LoREN Thoreau Ward. 



Handling Small Bolts Easily 



A TOOL for turning small bolts can 

 be made from a discarded socket 

 wrench. The handle of the wrench 

 should be cut off, and the protruding 

 spindle machined, as shown in the ac- 

 companying illustration. The finished 

 spindle will readily fit an ordinary "Yan- 

 kee" screwdriver. — B. G. McIntyre. 



Small bolts are easily handled with this 

 rebuilt socket wrench 



