788 



Popular Scieiice Monthly 



pending upon the form of the salt. If 

 the crystallized salts are secured, they 

 should be mixed with i part of salt to 

 2 parts of warm water. If the dry salts 

 are used, i part of salt sJioulil be mixed 

 with 5 jiarts of warm water. It is best 

 to mix the sokitiou imiiu-diatcly before 

 using. 



If storage - cells have been idle for 

 some time and have become badly 

 sulphated, the following treatment will 

 ordinarily put them in condition for 

 service again. First, the jars should 

 be thoroughly cleaned and the plates 

 dusted, after which the cells can be 

 assembled and the jars tilled with 

 electrolyte, having a specific gravity of 

 about 1. 215. Cells can then be charged 

 at 15 amperes for about 2 hours, after 

 which 14 pt. of a strong sohition of 

 sodium carbonate mixed with i i)art of 

 salt to 2 parts of water can ]>v added. 

 If the cells have been standing idle for 

 a great length of time it is better to mix 

 the sohui(jn with i (xirt of salt to i part 

 of water. They should then be charged 

 at a rate of from 12 to 15 amperes for 

 8 hours a day for 2 consecutive daj's. 

 The plates will look to be as good as new 

 after the sulphate has been removed by 

 this method. It is belter to remove the 

 de-sulphating solution after the plates 

 have been brought to a healthy condition 

 and replace it with the ordinary electro- 

 lyte. — A. Gemmell. 



shellacked or comjwunded. The result is 

 a very good pair of insulated i)liers. 



Making an Alternate Current Buzzer 

 From Old Bell Coils 



AKE two old bell coils and mount 



a wood base. Also 



of heavy clock-spring 



T 



them on 

 secure a piece 



Insulated Plier Handles 

 with Fuse Cases 



ELICCTRICAL men are often called 

 upon to make taps or splices on 

 wires carrying current. For this work 

 they need insulated plier hamiles. A 

 simple method of making these is shown. 



Buzzer made of old bell coils to work on 

 alternating current 



long enough to reach from one core to 

 the other. Solder one end to one core 

 and with a knife pry the other end so it 

 will not touch the core. Join the inner 

 wires of the coils together and the in- 

 strument iscomplete. — Ch.xrlesLoomis. 



A Home-Made Flood-Light Projector for 

 Construction Work 



THI'". accompanying illustration shows 

 a home-made flood-light jirojeclor 

 with tlie rellector made of an ordinary 

 tin pan. The tin 

 is large enough 

 to permit using 

 a 500-candle- 

 l^owcr nitrogen- 

 filled la m p , 

 whicli ismoimtetl 

 in tlu' center, as 

 shown. The tin 

 pan is supported 

 by means of a i' g- 

 in. gas pipe in 



Fiber tubes driven over plier handles to 

 form an insulation for electrical work 



Take two fiber tubes such as are 

 used in 600-volt fuses of about 30 am- 

 peres capacity. These can be forced over 

 the handles if they are driven by light 

 blows of a haMun<'r. A fiber or wood 

 plug is insertcil in the enils and then 



a 6AS Pipe 



A flood -light for 

 night workers 



such a way as to iiermit .uljustnuMit 

 of the projectors up and down tlu'ough 

 various angles. The two i)ipes in the 

 from of the projector are fitted with 

 ->l((\<s ,md two wing-screws, which 

 ])crmil them to be shortened or length- 

 ened. The rear pijic is arranged with a 

 universal joint, which acts as a hinge. 

 The universal joint could probably be 

 dispensi'd with by using .1 loose tec at 

 the bottom of the rear i)ipe. 



