DIRECT ACTION. 463 



A rocket in the act of ascent is shown in the uppermost figure 

 of the accompanying illustration. 



Below it is shown the Water Turbine, the principle of which 

 is evident from the sketch. 



From each of the apertures a stream of water is forcibly 

 directed, and, by its resistance, spins the vessel round and 

 round. There are several shops in London in which this 

 instrument may be seen at work. 



Although in such positions it is necessarily a mere toy, it 

 carries with it, in common with many other toys, the germs of 

 valuable inventions. Indeed, there have been attempts to 

 utilise the principle of Direct Action in the propulsion of 

 vessels, but as yet the mechanical difficulties have proved 

 practically insuperable, and, although a vessel has been thus 

 propelled, the expense has been heavier than that of the paddle 

 or screw, and the speed not nearly so great. 



On the right hand of the illustration is another example of 

 Direct Action, called the Electric Tourniquet. 



In the two previously mentioned instruments the motive 

 power is visible, but in this it is invisible except in the dark. 



The principle is exactly the same as in the pocket or water 

 tourniquet ; but, instead of heated air or a stream of water, 

 electricity is used. The instrument is attached to an electric 

 machine, and fully charged. The electric fluid rushes out of 

 the points, forces itself against the air, and so, by its recoil, 

 drives the machine round and round upon its pivot. 



WE will now take two examples of Direct Action as found 

 in Nature. 



Perhaps many of my readers have seen the Octopus, and 

 admired the manner in which it glides through the water, 

 trailing its long arms behind it. Whence the force comes is 

 not easily seen, and the creature appears to move almost by 

 volition. In reality, however, it employs Direct Action. It 

 takes water into the body, and then it ejects it through a 

 tube called the " siphon " with such force that the animal is 

 propelled backwards through the water. 



Some of the creatures belonging to the Cuttles, and popu- 

 larly called Squids, can use such extraordinary powers that 

 they can project themselves far out of the water. In con- 



