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GLEANINGS IN BEE CULTURE. 



July 15. 



would be rather more, without expensive 

 lubrication. Boys and girls who run bicycles 

 know how often their chains need lubricating 

 in this way. 



Now, within a short time a new method of 

 transmitting power, called " electrical trans- 

 mission," has come to the front. Without 

 doubt you have all seen dynamos. They are 

 generally run by a steam-engine. Well, a 

 dynamo may be in one building, and the ma- 

 chine propelled may be quite a distance away; 

 but the power may be conveyed by just two 

 little copper wires. As an experiment, our 

 whole machine-shop was run with full power 

 recently by two little wires no thicker than a 

 common brass pin; and while I write, a little 

 bit of motor, not much larger than a good- 

 sized watermelon, is working a pump down 

 on the creek bottom, fiOO feet distant, that 

 supplies soft water for our whole establish- 

 ment — in fact, for the whole neighborhood. 

 Now comes in the wonderful fact that caused 

 me to talk with you about electric transmission. 



When these little wires carry the power, do 

 they carry it like a belt so that some of it may 

 be lost by slipping, or are they absolute and 

 positive, like cogwheels or the chain-and- 

 sprocket wheels ? Electricity is such an er- 

 ratic, slippery agent, we might suppose it 

 would " slip a cog," or a great many of them, 

 without knowng the difference. Perhaps I 

 should beg pardon of electricity for speaking 

 thus lightly of its wonderful powers. Well, 

 strange to tell, transmission by the electric 

 fluid is positive, like gearing. When we in- 

 stalled our 35-horse-power dynamo, took down 

 our belting and shafting, and ran two little 

 wires up to the pressroom to the motor, I 

 watched the thing with much curiosity, and 

 was greatly surprised when the press and all 

 the other machinery ran just as steadily, or 

 perhaps more so, if any thing, than when the 

 great cumbersome belting and shafting carried 

 the power from the engine. I said to the 

 boys, " Why should that motor go just so fast 

 and no faster? Why doesn't it go slower 

 when you attach heivy machinery, and espe- 

 cially machinery that has to get over points of 

 great special resistance at every revolution, 

 as is the case with our big press? " 



The boys explained to me that the electric 

 motor had got to go just so fast and no faster; 

 that is, if our engine is made to move at a 

 certain speed by means of a governor, the 

 motor, or, if you choose, all ihe different 

 motors, take up a particular rate, and each 

 one is marie to run so fast and stick right to it. 

 The electric current neither jumps ahead nor 

 lags behind. It is right there, steady and 

 true, hour after hour, day and night. 



" But," said I, " suppose we hold that motor 

 back by some tremendous resistance — what 

 then?" 



The boys answered, "Why, it would spoil 

 the machine if you were to hold it still. Look 

 here. Here is an apparatus called a rheostat 

 that cuts off the current and stops the machine 

 before any thing can break. It is a sort of 

 safety-valve or safety-appa-atus to prevent 

 damage by awkward manipulation." 



Now, this whole matter filled me with won- 



der and surprise ; and it fills me with wonder 

 and surprise even yet. But this is not all of 

 it. vSaid I : 



"Does this motor here in the press-room 

 run at exactly the same speed as the dynamo 

 in the engine-room ? " 



" Oh! no, father. This little motor up here 

 runs very much faster than the dynamo or 

 generator down by the engine." 



" But what makes it go faster? How in the 

 world does the thing know how fast it ought 

 to go, and why does it stick right there with- 

 out going at any other speed ? " 



In studying into this curious matter of elec- 

 tric transmission, I overhauled not only Ernest, 

 my .Sd-year-old boy, but Huber too, our 14- 

 year-old electrician. They both explained to 

 me that the speed of the motor depended on 

 the size of the wire composing it, and on the 

 way the wires are wound. The motor is made 

 to go at such a speed when the generator that 

 furnishes the power is run at a designated and 

 particular speed. This aroused my curiosity 

 again. 



"Why, look here, boys, can you multiply 

 speed by these different motors in the way 

 they are wound ? Can yon make a motor 

 that, when put on the shaft of a buzz-saw, will 

 give the saw sufficient speed to do its work 

 while the generator runs at about the same 

 speed as the flywheel of the engine? " 



The boys answered, "Yes, it can be done, 

 and has been done to some extent; but it 

 costs a great deal more to make generators 

 that run very slowly, and it also costs a great 

 deal more to make motors that run very fast, 

 like a buzz-saw. At the present stage of me- 

 chanical and electrical science it is cheaper to 

 multiply speed to a certain extent by means 

 of belting and pulleys. For this reason you 

 generally see the generator in a large plant 

 running a good deal faster than the engine 

 that propels it." 



Now, alongside of these facts comes another 

 curious thing. When you move a machine 

 that requires many horse power to turn it, the 

 belt must be very wide, very long, and it must 

 pull with a great deal of force on the machine 

 in order to make it "hug" the pulley. For 

 this reason machinery has to be set on foun- 

 dation that is very expensive or else it will 

 pull loose. The power pulls on one side. 

 You can readily see this in a thrashing- 

 machine; but a machine may be propelled by 

 electricity — that is, where the motor is placed 

 right on the main driving-shaft, and the 

 machine need be anchored scarcely at all. It 

 can rest on the floor of the room ; and as only 

 these little wires are attached to it it can be 

 moved to any spot or angle you choose ; for 

 the electric force pushes right round the shaft 

 on all sides alike. 



I discovered yesterday, in riding my chain- 

 less bicycle up some long high hills, that I 

 could climb them very much easier when I 

 pushed and pulled on the cranks with my toes. 

 Yes, you can push and pull with your toes 

 when you learn the trick. Stick your toe 

 upward when the crank is at its highest point, 

 and crowd it from you. At the same time, 

 stick your other toe downward and push back 



