THE GYROCAR 



point on which it rests; it is seeking a position of 

 equilibrium, which, owing to the location of its centre 

 of gravity, will be found when its spindle is erect. But 

 a top supported at both ends and properly balanced, 

 does not tend to rise but only to maintain its position. 



HOW THE BRENNAN GYROSCOPES WORK 



It is such a balanced top as this that we must call to 

 our aid in explaining the action of Mr. Brennan's gyro- 

 scopes. The explanation will involve the use of a dia- 

 gram perhaps rather unpleasantly suggestive of the days 

 when you studied geometry, and I fear I cannot hope to 

 make interesting reading of the explanation. But it 

 will be worth your while to follow it, that you may under- 

 stand the action of one of the most remarkable and 

 ingenious of inventions. Figure i represents a kind of 

 top called a Foucault gyrostat. It is merely a top or 

 gyroscope in gimbal frames, such as I have already re- 

 ferred to. With certain slight modifications, the dia- 

 gram that represents it might also be a diagram of one of 

 the gyroscopes in Mr. Brennan's car. Indeed, it was 

 such a top as this that led Mr. Brennan to his discovery. 

 Once while on a visit to Cannes, he purchased a top like 

 this of a street vender — and the gyrocar is the outcome 

 of the studies he made with it. This is also the kind of 

 top with which Foucault, after whom it is named, proved 

 that the earth revolves; but we shall come to that story 

 in another connection. 



Reverting to the diagram, the gyroscope or top proper 

 is at the centre, revolving on the axis O A, It is 



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