CHARLES B. WARRING. 151 
that nevertheless it rose to a vertical. I had observed 
the same thing, but did not mention it in my paper, be- 
cause in all my experiments where this occurred, the 
depression had been somewhat larger than the ‘‘ point ”’ 
and consequently permitted it to travel around in a small 
circle, hence I could not see that there was any real 
contradiction of what I had said. 
After receiving Mr. Blish’s letter I devised what seems 
to me an experimentum crucis, for it permits freedom of 
rotation and of gyration,’ and yet prevents the ‘‘ point”’ 
from traveling. The arrangement for this purpose is 
ll Z 
of a hollow cone in which the circumference of the 
‘‘ point’? touches allaround, thus preventing any motion 
of translation. The ‘‘point,’’ it will.be noticed, is of 
considerable size, and flat—a form most favorable for 
causing a top to rise. On trial I found that the top, 
although revolving freely, both on its own axis and 
about a vertical one, would not rise. I then placed it 
on a pane of glass, thus allowing it to travel, and it rose 
quickly to a perpendicular. 
T think this suffices to show that Mr. Blish’s experi- 
ment proves only that the ‘‘point”’ of the top does not 
need to travel very much, and as in that I agree with 
him, I do not see that he proves anything against my 
statement. 
1 All through these papers, gyrate and gyration are used to denote the revolution of the 
gyrating body around a vertical axis, while rotate and rotation refer to its revolution on 
its own axis. 
SS 
