202 AN EMPIRICAL STUDY OF GYRATING BODIES. 



The Top 142 



Why it does not fall, 144 



Its backward motion after falling 145 



Tops whose " points " are not points, 146 



Gen. Barnard's idea about Tops, 146 



Why does the Top rise, 148 



The sleeping of the Top, 149 



Why Tops run about the floor, 150 



How to change the obliquity of the Top, .... 150 



" Rapid Rotation." (Note) 151 



Another Paradox, 152 



Tracings made by the Top, 152 



The Gyrostat, 153 



The rationale of, 155 



Effect of pushing the foot-piece, 156 



The Gyrostat on Wheels 157 



The Gyrostat on Stilts 158 



Gyrostatic Trapeze, 160 



Thomson & Tait's "Stabilities," 161 



Gyrostat on a tight-rope, 161 



The Gyrocycle, . 163 



Bohnenbergher's Machine, 163 



Effect of pressure on the axle, 165 



The Earth as a Gyroscopic Body, 166 



Frisi's Law, 167 



Note on the same, 200 



Precession, 170 



If no orbital motion, 171 



With orbital motion, 173 



Difference between Precession of Earth and of Top, . .174 



Causes affecting rate of Precession. 174 



Nutation, 175 



The pull is always toward the ecliptic, 177 



Experimental verification of Nutation, 179 



New Law of Nutation, 180 



What Sir John Herschel says, 181 



What Professor Nichol says, 182 



Note on Nutation 182 



The Gyrostatic Balance, 184 



The horizontal rotation not due to friction, . . . .189 



Why the Gyrostats do not act against each other, . . 190 



Mr. George Forbes's idea 192 



Gyrostatic Dipping-Needle, 194 



The Gyroscopic Pendulum, 195 



Note on Frisi's Law, 200 



186 



