"waters above the heavens," because it is made of ice.

For centuries the authority of these three great teachers was
unquestioned, and in countless manuals and catechisms their doctrine was
translated and diluted for the common mind. But about the second quarter
of the twelfth century a priest, Honorius of Autun, produced several
treatises which show that thought on this subject had made some little
progress. He explained the rain rationally, and mainly in the modern
manner; with the thunder he is less successful, but insists that the
thunderbolt "is not stone, as some assert." His thinking is vigorous
and independent. Had theorists such as he been many, a new science could
have been rapidly evolved, but the theological current was too strong.
(207)

(207) For Rabanus Maurus, see the Comment. in Genesim and De Universo
(Migne, Patr. Lat., vol. cvii, cxi). For a charmingly naive example of
the primers referred to, see the little Anglo-Saxon manual of astronomy,
sometimes attributed to Aelfric; it is in the vernacular, but is
translated in Wright's Popular Treatises on Science during the Middle
Ages. Bede is, of course, its chief source. For Honorius, see De
imagine mundi and Hexaemeron (Migne, Patr. Lat., vol. clxxii). The De
philosophia mundi, the most rational of all, is, however, believed by
modern scholars to be unjustly ascribed to him. See note above.

The strength of this current which overwhelmed the thought of Honorius
is seen again in the work of the Dominican monk, John of San Geminiano,
who in the thirteenth century gave forth his Summa de Exemplis for the
use of preachers in his order. Of its thousand pages, over two hundred
are devoted to illustrations drawn from the heavens and the elements.
A characteristic specimen is his explanation of the Psalmist's phrase,
"The arrows of the thunder." These, he tells us, are forged out of a dry
vapour rising from the earth and kindled by the heat of the upper air,
which then, coming into contact with a cloud just turning into rain,
"is conglutinated like flour into dough," but, being too hot to be
extinguished, its particles become merely sharpened at the lower end,
and so blazing arrows, cleaving and burning everything they touch.(208)

(208) See Joannes a S. Geminiano, Summa, c. 75.

But far more important, in the thirteenth century, was the fact that the
most eminent scientific authority of that age, Albert the Great, Bishop
of Ratisbon, att