636 



Popular Science Monthly 



A Bracing for an Iron Pipe 

 Fence Post 



THE illustration shows how a fence, 

 the posts of which were ordinary iron 

 pipe, was braced with a bent piece of the 

 same sized pipe so as to stand a severe 



Pip© 



A curved post brace set in concrete to make 

 a solid support for stretching wire tightly 



pull when the wire fencing was stretched 

 on it. The brace and the posts were filled 

 with cement, and the ring was inserted 

 in it. The ring was shaped from a piece 

 of heavy, flat wrought iron, which had 

 enough shank to fit solidly into the pipe. 

 The bases for the posts were built first 

 and the remainder of the concrete work 

 was left until later on, so that should any 

 cracks develop along the edge of the post 

 base they could be easily located and 

 remedied. — James M. Kane. 



Attaching Linoleum to a 

 Cement Floor 



A GOOD cement for attaching linoleum 

 to a cement floor may be made as 

 follows: Manila gum 15 parts, brown rosin 

 20 parts and thick turpentine 45 parts, all 

 by weight. "Pulverize the rosin and gum 

 and heat until melted; then thin out with 

 denatured alcohol, using 20 parts. 



Casing for Carrying Tube Cements 

 Without Damage 



HAVING trouble keeping the rubber 

 cement tubes in the tool bag of my 

 bicycle clean, I 

 devised the 

 tube-carrying 

 case shown in 

 the illustration. 

 It consists of a 

 brass tube about 

 1 in. longer than 

 the cement tube and a little larger in 

 diameter, with one end plugged and the 

 other corked. — Axel H. Johnson. 



Drasstube-^ Cork' 



Small brass case in- 

 closing tubt cement 



A Silver-Plating Bath and How 

 to Use It 



THE most important attribute for the 

 amateur plater to cultivate is caution. 

 He is working with some of the most 

 deadly poisons known to chemistry. He 

 should not inhale the fumes given off in 

 mixing solutions and should not get these 

 solutions on his hands or clothing. No 

 vessel employed in plating should be used 

 for any other purpose. • 



The electric current for plating should 

 be supplied by some form of steady 

 current battery, giving low voltage and 

 high amperage, such as the Edison primary, 

 Bunsen, or Fuller cells. The cells of the 

 battery should be connected in parallel. 

 The current must not be above two volts. 

 For the anode, purchase a sheet of pure 

 silver from a jewelry supply house. The 

 sheet surface should contain from 1 to 4 

 sq. in. Such a plate 1/32 in. thick will 

 cost from 75 to 90 cents. The position of 

 the anode should be adjustable; so that 

 more or less of its surface can be immersed, 

 and so that it may be moved toward or 

 away from the article being plated. 



A pair of heavy wires should be provided, 

 long enough to reach across the top of the 

 plating tank. When placed in position 

 the wire carrying the anode is connected 

 with the carbon of the battery, and the 

 one carrying the article to be plated is 

 connected with the zinc. Cut several 

 lengths of No. 14 or No. 16 copper wire; 

 bend into a hook at the top, to hang on the 

 rod connected with the zinc, and long enough 

 to reach to the bottom of the tank. These 

 are called "slinging wires," being twisted 

 around the work suspended in the solution. 



The next operation is to mix the solutions. 

 Only pure chemicals should be used. Grad- 

 uates, mixing vessels, evaporating dishes, 

 mixing rods, etc., must be chemically clean. 

 Use glass rods or tubing for stirring rods. 



The nitrate of silver bath is made by 

 dissolving pure scrap silver in a 25 per cent 

 nitric acid solution. After the solution has 

 been evaporated, the resultant crystals are 

 dissolved in two quarts of distilled water. 

 In another vessel, mix 1 oz. of potassium 

 cyanide crystals in water, and add this 

 slowly to the silver nitrate solution. 

 Enough of the two solutions have been 

 mixed when a precipitate forms. The 

 liquid should be poured carefully from 

 the material in the bottom, which is silver 

 cyanide. This precipitate should be thor- 

 oughly washed in pure cold water. 



