920 



Popular Science Monthly 



A Hose Connection Guaranteed 

 Water-Tight 



THE hose connection illustrated, has 

 an upper part with a tapered end to 

 fit the rubber washer in the large end 

 of the lower part. Near the end of 

 each part, which engages the hose, is 

 an enlargement to keep the hose from 



\^^. /Rubber i\''as/?er 



r 



-<^-- 



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Diagram giving proper dimensions of 

 hose connection 



slipping off. Small clamps can also be 

 used. Each flange consists of 2 segments 

 of a circle, 90°, each opposite the other 

 and tapered, or rather increasing in 

 thickness, so that after the 2 parts are 

 placed together, a 90° turn, and some- 

 times less, will make the connection 

 perfectly tight. — Joseph K. Long. 



— •■ r -K-t -,+ -1+ - L-T ,] 



H^ 



A ninety-degree turn makes this connec- 

 tion perfectly tight 



Silver-Plating Glass 



HERE is a good recipe for silvering 

 mirrors or silver-plating glass of 

 any kind. 



Two solutions are used. For con- 

 venience they may be designated as solu- 

 tion No. I, and solution No. 2. 



Solution No. i is prepared as follows: 

 To a one per cent solution of silver 

 nitrate add pure aqua ammonia, drop 

 by drop, till the precipitate is almost all 

 dissolved. Let this stand and then 

 filter. The filtrate is solution No. i. 



To prepare solution No. 2 : Dissolve 

 one gram (.04 oz.) of silver nitrate in a 

 little water and add to 500 cubic 

 centimeters (17 fluid ozs.) of boiling 

 water. Then dissolve 0.85 gram (13.12 

 grains) of Rochelle salts in a little water 

 and add to the 500 cubic centimeters of 



boiling water containing the silver 

 nitrate. Boil for 20 or 30 minutes till 

 the gray precipitate has collected, and 

 filter the solution. This filtrate is 

 solution No. 2. 



The glass surface to be coated must 

 be carefully cleaned with alcohol to 

 remove all traces of grease and dirt. All 

 other surfaces which are not to be 

 coated, should be painted with melted 

 paraffin after the glass has been cleaned 

 with alcohol. This leaves a clean 

 exposed surface on one side of the glass 

 to which the silver will stick. In coating 

 with the paraffin, be careful not to get 

 any on the clean surface. Mix equal 

 parts of solutions No. i and No. 2, and 

 place the glass to be coated in the solu- 

 tion. The silver will stick better if the 

 clean exposed surface of the glass is 

 rubbed with a small cotton swab, 

 saturated with the solution. Leave the 

 glass in the solution till the coating of 

 silver is as heavy as desired. Then 

 scrape off the paraffin, being careful not 

 to mar the silver deposit on the rest of 

 the glass. If desired, to protect the 

 silver coating, two thin coats of white 

 shellac may be applied. — L. G. Haskell. 



How to Mend a Broken Casting 



WHILE placing a casting in his 

 lathe, ten years ago, a machinist 

 permitted it to drop on the tailstock, 

 breaking the casting, as shown in the 

 illustration. It was a serious break in 

 those days, when cast-iron could not be 

 welded so readily as now. The only 

 recourse was a harness of two turned 

 rings and two bolts. The arrangement 

 may be seen in the illustration; it does 

 not look good, but it is still doing 

 service. — N. G. Near. 



This mended casting has done service for 

 ten years 



