MIRACLES OF SCIENCE 



izer for ships to prevent their rolling at sea. Prom- 

 inent workers in this field were Sir Philip Watt, Pro- 

 fessor Biles, and the elder Freud in England and in 

 Germany Herr Frahm and Dr. Schlick. Mr. Louis 

 Brennan, in England, developed in 1907 a monorail 

 car, balanced by a gyroscope, which excited great in- 

 terest when exhibited before the Royal Society. After 

 this numberless workers took up the problem, with 

 reference to one or another of its aspects ; but no one 

 else, perhaps, has attained so large a measure of suc- 

 cess as the American, Mr. Elmer A. Sperry, who has 

 had the assistance in much of his experimental work 

 of the young engineer, Mr. H. C. Ford, and of Mr. 

 Carl Norden. It is the Sperry gyroscope in its vari- 

 ous applications that I wish chiefly to describe in the 

 ensuing pages. 



THE GYROSCOPE COMPASS 



When Foucault made his classical experiments he 

 stated that a very pretty demonstration might be 

 made by pointing the axis of the gyroscope at a star 

 and noting that the axis continues to point toward 

 the same star. "If we select a suitable star," he says, 

 "or if we aim at one of the points of the heavens which 

 appear to be moving most quickly, the axis of rota- 

 tion when carefully examined will be found to share 

 the same apparent displacement and will give em- 

 phatic evidence of the earth's movement." But he 

 adds: "Of course, one should not point the axis in 

 the direction of the polar star, because this star, not 

 having any apparent movement, the instrument would 

 act similarly and not indicate the earth's motion." 



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