1911-12.] On Novel Illustrations of Gyrostatic Action. 413 
the gyrostat to precess in the direction which results in the centre of 
gravity of the balancing rod being moved so as to counteract the tilting 
couple. The experiment is interesting inasmuch as the gyrostat detects 
the tendency of the apparatus to fall, and immediately corrects it. 
Fig. 6. — Acrobatic Top. 
In figures 6 and 7 are shown two new tops, of which the construction 
will be clear from the diagrams. In the top illustrated in fig. 6 a large 
gyrostat carries a framework made of stiff wire. To this framework is 
attached, by means of two sleeved joints as shown, a small gyrostat. The 
