Popular Science Monthly 



775 



A Scheme for Soldering Metals 

 Difficult to Join 



MANY times wluMi soldering together 

 different metals which do not join 

 easily it is better to put acid on each 

 piece and fasten the solder to it separate- 

 ly. The pieces can then l)e soldered to- 

 gether without using more acid. 



This method is especially advanta- 

 geous for fastening two pieces together, 

 where if acid were used, it might run 

 into places difficult to reach with a 

 cleaning cloth so that it could not be 

 wiped away and would corrode the metal. 



A Heat Deflector for a Hot Air 

 Register 



A SHEET metal canopy placed over 

 the ordinary hot air register will 

 direct the heat toward the bottom of the 



The metal canopy deflects the hot air 

 outward and down toward the floor 



room where it is most needed. Strips 

 of fairly heavy metal about 7 in. wide 

 are cut as shown in the illustration. The 

 back is turned in at an angle of 90 deg. 

 and fits in behind the register. After 

 the canopy has been bent into shape the 

 screws in the register are loosened and 

 the back slipped behind it. Then the 

 screws are replaced. — E. C. Stilweli,. 



How to Straighten the Crooked 

 Straws of a Broom 



TAKE a pail of boiling hot water and 

 completely immerse the straw end 

 of the broom for ten minutes. After the 

 straws have become completely soaked, 



withdraw the broom and suspend it by 

 the liandle. When the straws are dry 

 they will be found to be perfectly 

 straight. — E. Huntsman. 



An Automatic Cleaner 

 for Bicycle Hubs 



HUBS of bicycles readily collect dirt, 

 and because of the spokes they are 

 very hard to clean. With the little 



k 



The weight of the 

 chain link keeps the 

 leather from turn- 

 ing with the wheel 



de\'ice illustrated 

 the cleaning is 

 done automatically 

 and the surface 

 kept polished. The 

 device consists of a piece of leather 

 shaped as shown, then hung over the 

 hub, the ends being fastened with a 

 link of chain. This link besides holding 

 the leather on the hub is also conve- 

 nient for repairing a broken chain in an 

 emergency. — M. J. Silverstein. 



An Improved Force-Filter Which 

 Is Easily Cleaned 



MOST force-filters, used for rapid 

 quantitative work, catch the fil- 

 trate in flasks, which are often hard to 

 clean after a filtration, especially if some 

 of the precipitate passes through the 

 filter-paper. 



This disad\'antage can be overcome b>- 

 catching the filtrate in a beaker under a 

 bell-glass, with a top for a two-hole rubber 

 stopper. A funnel is inserted with a 

 glass tube which is connected b>- means 

 of a rubber tube to an aspirating-pump. 

 If the suction is strong, a platinum cone 

 should he placed in the funnel to prevent 

 the paper from tearing. The glass or 

 metal plate, upon which the bell-glass 

 rests, should have a slight coating of 

 some sticky, pasty material, such as that 

 used on the disk of an exhaust pump, 

 which will render the contact perfectly 

 air-tight. — Ed\v.\rd Mutch. 



