ation of the Sun's and heavenly bodies' heats, that pass
divers inequalities, and (as it were) orbs, progresses, and returns,
whereby we produce admirable effects. Besides, we have heats of dungs;
and of bellies and maws of living creatures, and of their bloods and
bodies; and of hays and herbs laid up moist; of lime unquenched; and
such like. Instruments also which generate heat only by motion. And
farther, places for strong insulations; and again, places under the
earth, which by nature, or art, yield heat. These divers heats we use,
as the nature of the operation, which we intend, requireth.

"We have also perspective-houses, where we make demonstrations of all
lights and radiations; and of all colours: and out of things uncoloured
and transparent, we can represent unto you all several colours; not in
rain-bows, (as it is in gems, and prisms,) but of themselves single.
We represent also all multiplications of light, which we carry to great
distance, and make so sharp as to discern small points and lines. Also
all colourations of light; all delusions and deceits of the sight, in
figures, magnitudes, motions, colours all demonstrations of shadows.
We find also divers means, yet unknown to you, of producing of light
originally from divers bodies. We procure means of seeing objects afar
off; as in the heaven and remote places; and represent things near as
afar off; and things afar off as near; making feigned distances. We
have also helps for the sight, far above spectacles and glasses in use.
We have also glasses and means to see small and minute bodies perfectly
and distinctly; as the shapes and colours of small flies and worms,
grains and flaws in gems, which cannot otherwise be seen, observations
in urine and blood not otherwise to be seen. We make artificial
rain-bows, halo's, and circles about light. We represent also all
manner of reflexions, refractions, and multiplications of visual beams
of objects.

"We have also precious stones of all kinds, many of them of great
beauty, and to you unknown; crystals likewise; and glasses of divers
kinds; and amongst them some of metals vitrificated, and other
materials besides those of which you make glass. Also a number of
fossils, and imperfect minerals, which you have not. Likewise
loadstones of prodigious virtue; and other rare stones, both natural
and artificial.

"We have also sound-houses, where we practise and demonstrate all
sounds, and their generation.