THE GYROSCOPE FOR MARINE PURPOSES. 151 



treatise on practically all the phases and bearings of this question, including 

 an original investigation of the underlying phenomena of the gyroscope 

 itself. It is of the greatest value to this important art that its problems 

 should have come under the observation and been reviewed by so able a 

 mathematician, experienced in all branches of experimental research, and 

 fitted by long training to judge of the practical bearings of the results extend- 

 ing, as does this experience, to the very largest undertakings and structures 

 in marine work. To give some idea of the great amount of work involved 

 and also of the abstruse character of this work, I take the liberty of here 

 reproducing (Plate 57) an isolated page of Captain Taylor's forty-page 

 treatise above referred to. It is to be hoped that the author himself may 

 be prevailed upon to give the Society a paper including this valuable treatise. 



The practical effect in operation of the active type of gyroscope is to 

 secure a large reduction of weight over and above that possible with the 

 passive type. One of the reasons for this becomes apparent from the action 

 of the pendulum which we have canvassed. With the smaller angles of 

 roll, the gyroscope would have to be large enough so that its small angles of 

 response would develop the required energy for extinguishing or still further 

 reducing the roll, complete extinguishment being impossible ; whereas with 

 the active type the full 180 degrees oscillation of the gyroscope is always 

 available, where required, for the extinguishment of large or even the 

 smallest angles of roll as necessary. Thus an extremely small machine, 

 taking advantage of the larger angles, between twenty and thirty times 

 as large, is sufficient to accomplish this purpose. 



Plate 58 illustrates three curves, one at the top giving the number 

 of oscillations of the ship's model before it was brought to rest by the natural 

 friction, having been originally tilted to 25 degrees to one side of the center. 

 The shorter or central curve illustrates the number of oscillations of the 

 model with the gyroscope acting passively or on Dr. Schlick's plan, the 

 several rolls of smaller magnitude at the end being omitted where the pas- 

 sive type of gyroscope failed to respond; and a still shorter curve at the 

 bottom shows the number of oscillations of the ship in being brought to 

 rest, absolute freedom from motion being possible by the same gyroscope 

 when operated actively. These are among the interesting results reached 

 in the investigations referred to above. 



When the motive power of vessels changed from an upsetting force 

 to one almost exclusively of forward thrust, the design of ships underwent 

 quite radical changes in connection with lines affecting the stability, decreas- 

 ing this factor and favoring decreased resistance, aiding the attainment 

 of higher speeds. Now that stability may be imparted to a structure of 



