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more or less familiar with it, I shall recount the principal 
things I noticed whilst observing it critically. 
The ball was very light and had a wet surface. 
The jet, when free from the ball, would rise about three 
feet. 
The ball was not kept in one position, but oscillated up 
and down. 
The centre was not necessarily over the jet, it often re- 
mained for a long time on one side of it. In fact it appeared 
to be in equilibrium when struck about 45° from its middle. 
In this way, for some seconds at a time, the ball appeared 
as though it were hanging to the jet, and then it would 
oscillate about this position so far, that at times it would be 
struck underneath, and at other times almost on the hori- 
zontal circle; indeed sometimes it would be forced so much 
to one side that the jet missed it altogether. In this case it 
would immediately drop down, but such was its determina- 
tion not to be thrust aside, that it generally came back into 
the jet almost instantly. Occasionally, however, it would 
fall down into the basin. 
Being a light ball the friction of the water caused it to 
spin, and as it moved about the jet it would spin sometimes 
in one direction and sometimes in another, always about a 
horizontal axis. 
Of the water which strikes the ball, part is immediately 
splashed off in all directions, part is deflected off at a tan- 
gent, and part adheres to the ball, and is carried round with 
it until it is thrown off by centrifugal force. 
There are many other things that attract attention, but 
I think I have noticed those which bear on the explanation. 
The vertical force caused by the action of the jet is no 
doubt amply sufficient to support the weight of the ball, 
and did the centre of the ball remain vertically over the 
jet there would be no difficulty. 'The only explanations I 
have ever heard have been based on the same supposition : 
