FREE BOOKS

Author's List




PREV.   NEXT  
|<   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27  
28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   >>   >|  
S OF A RADIO-ENGINEER TO HIS SON LETTER 1 ELECTRICITY AND MATTER MY DEAR SON: You are interested in radio-telephony and want me to explain it to you. I'll do so in the shortest and easiest way which I can devise. The explanation will be the simplest which I can give and still make it possible for you to build and operate your own set and to understand the operation of the large commercial sets to which you will listen. I'll write you a series of letters which will contain only what is important in the radio of to-day and those ideas which seem necessary if you are to follow the rapid advances which radio is making. Some of the letters you will find to require a second reading and study. In the case of a few you might postpone a second reading until you have finished those which interest you most. I'll mark the letters to omit in this way. All the letters will be written just as I would talk to you, for I shall draw little sketches as I go along. One of them will tell you how to experiment for yourself. This will be the most interesting of all. You can find plenty of books to tell you how radio sets operate and what to do, but very few except some for advanced students tell you how to experiment for yourself. Not to waste time in your own experiments, however, you will need to be quite familiar with the ideas of the other letters. What is a radio set? Copper wires, tinfoil, glass plates, sheets of mica, metal, and wood. Where does it get its ability to work--that is, where does the "energy" come from which runs the set? From batteries or from dynamos. That much you know already, but what is the real reason that we can use copper wires, metal plates, audions, crystals, and batteries to send messages and to receive them? The reason is that all these things are made of little specks, too tiny ever to see, which we might call specks of electricity. There are only two kinds of specks and we had better give them their right names at once to save time. One kind of speck is called "electron" and the other kind "proton." How do they differ? They probably differ in size but we don't yet know so very much about their sizes. They differ in laziness a great deal. One is about 1845 times as lazy as the other. That is, it has eighteen hundred and forty-five times as much inertia as the other. It is harder to get it started but it is just as much harder to get it to stop after it is once started or to change its dire
PREV.   NEXT  
|<   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27  
28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   >>   >|  



Top keywords:

letters

 

specks

 

differ

 

reading

 

reason

 

batteries

 
plates
 

harder

 

started

 
experiment

operate

 

things

 

receive

 

messages

 
audions
 

crystals

 
electricity
 

copper

 

change

 

interested


telephony
 

dynamos

 

ELECTRICITY

 

MATTER

 

ENGINEER

 
laziness
 

eighteen

 

energy

 

LETTER

 

inertia


electron

 

proton

 

called

 

hundred

 

explain

 
operation
 

interest

 
finished
 

postpone

 

sketches


written

 
understand
 

commercial

 

follow

 

series

 

important

 
advances
 

listen

 
require
 
making