We analyze passages of Galileo’s writings on aspects of floating. Galileo encountered peculiar effects such as the “floating” of light objects made of dense material and the creation of large drops of water that were difficult to explain because they are related to our current understanding of surface tension. Even though Galileo could not understand the phenomenon, his proposed explanations and experiments are interesting from an educational point of view. We replicate the experiment on water and wine that was described by Galileo in his Two New Sciences.

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11.
“… [this] is shown to us by the experiment of two glass vessels—called montevins—the upper one of which being filled with water and the lower with wine, when placed one on top of the other, one manifestly sees the wine mount to the top across the water and the water descend across the wine, without their becoming mixed together…” (Ref. 10).
12.
The density of the wine was measured by a Mohr–Westphal’s balance at 24°C and yielded 0.991±0.001g/cm3. It is “almost inappreciably lighter than water,” as Galileo says, because water’s density is 0.997g/cm3 at the same temperature.
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H. N. V.
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15.
In the original text, Mass or Masse is “mole,” which in Italian stands for “bulk,” or “volume” in modern physics parlance.
16.
Augmentation of gravity is equivalent to “increase of the specific weight.” Also, in the following, the word gravity stands for specific weight.
17.
Greater Lightness is equivalent to “decrease of the specific weight.”
18.
Reference 4, pp.
3
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19.
Reference 4, pp.
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20.
Reference 4, pp.
38
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