��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
��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 the 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.