Of these, the _Bowls_ appear to be the most attractive. One on the first
piece, _by fire_ was a little glass bowl filled with clear water. This
bowl was about three inches diameter, placed in the middle of another
sphere, about six inches diameter, consisting of several iron rings or
circles, representing the hour circles in the heavens. The hour was
known by applying the hand to these circles when the sun shone, when
that circle where you felt the hand burnt by the sunbeams passing
through the bowl filled with water, showed the true hour, according
to the verse beneath it:
Cratem tange, manusq horam tibi reddet adusta.
The phenomenon is thus explained by the Professor: "the parallel rays of
the sun passing through the little bowl, are bent by the density of the
water, into a cone or pyramid, whose vertex reaches a little beyond
those hour circles, and there burns the hand applied; for so many rays
being all united into a point, must needs make an intense heat, which
heat is so powerful in the summer-time, that it will fire a piece of
wood applied to it."
To many of the Dials were suitable inscriptions as above, and these with
the references must have made the construction of the whole a task of
immense labour. It would be absurd to expect that Charles II.
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