Fig. 59. A RESISTANCE BOX FOR MEASURING THE RESISTANCE OF WIRES
A large number of electrical devices call for winding wire on cores, spools, coils, etc. Nearly all windings can be done on a lathe but if a lathe is not among your treasured possessions you can make a winder which will serve all ordinary purposes. The drawings shown at A and B, Fig. 60, give all the details of construction and you can make one chiefly of wood of whatever size your winding calls for.
Fig. 60. AN EASILY MADE WINDING DEVICE
A. A side view
B. An end view
How to Experiment with Chemistry.—It is a pleasant pastime to make chemical experiments after a known formula but it is quite a different and a difficult thing to try to invent some new chemical compound when you know little or nothing of chemistry.
If your invention calls for some chemical combination or decomposition or double decomposition—these are the three kinds of chemical action—get an elementary book on chemistry and study it until you really know it and then you will have a bed-rock foundation on which to build up your invention.
You may say it is all very well to read a book on chemistry and learn all about it but it’s a mighty hard thing to do without a teacher. My answer is if you are not interested in chemistry, you will certainly find the study of it up-hill work and very tedious.
But if you are working on an invention like, say, synthetic gems, that is making real rubies and sapphires and emeralds in an oxy-hydrogen furnace, see Fig. 61, you will not only study but you will study harder than you have ever studied before if you believe it will help you to find the solution of the gem problem. It is under these conditions that work-study becomes play-study and you will be fascinated with it and it will then prove pleasant as well as profitable.
