( up ) 
on which is fcrewed on one of the little Difiles, which 
are made of Ivory : Of thefe I have feveral Sizes, 
from three Quarters to one Tenth of an Inch Diame- 
ter. W ten any one of thefe little VelTels is filled with 
Water, fo as that it may Hand above the Brims of the 
Cup, and has acquired a Spherical Surface (as it will 
do in thefmalleft Cups) let it be fet on the Table with 
the little Stand to which it had before been fcrewed, or, 
which is betrer, upon the larger Stand mentioned above, 
the great Diih being taken off, and the frnall plain 
Top fcrewed on ; being thus prepared, let the Tube be 
excited, and held over the Water at the Diftance of 
about an Inch or more. If it be a large Tube, there 
will firft arife a little Mountain of Water from the Top 
of the Drop, of a conical Form, from the Vertex of 
which there proceeds a Light (very vifible when the 
Experiment is performed in a dark Room) and a flap- 
ping Noife, almoft like that when the Fingers are held 
near the Tube, but not quite fo loud, and of a more flat 
Sound: Upon this immediately the Mountain, if I may 
focall it, falls into the reft of the Water, and puts it 
into a tremulous and waving Motion. I h ;ve now a 
few Days (ince repeated this Experiment in the Day- 
time, where the Sun fhined : I perceived that there 
were final! Particles of Water thrown out of the Top 
or the Moutr, and that fometimes there would arife 
a very fine Stream of Water from the Vertex of the 
Cone, in the manner of a Fountain, from which there 
iflued a fine Steam, or Vapour, whofe Particles 
were fo fmall as not to be feen ; yet it is certain that 
it mull be fo, fince the under Side of the Tube was 
wet, as I found when I came to rub the Tube again j 
and I have fince found, that though there does not 
always 
