Natural History
Natural History
'Why is the fish in the water swifter than the bird in the air when it ought to be the contrary, seeing that the water is heavier and thicker than the air, and the fish is heavier and has smaller wings than the bird?'
Lobsters and crabs are empty at the waning of the moon, for there is little light for them to feed themselves by, and if one brings them a Hght at night they all hasten to this light.
And when the moon is at the full they see their food well and eat of it abundantly. c.a. 165 v. b
Why is the fish in the water swifter than the bird in the air when it ought to be the contrary seeing that the water is heavier and thicker than the air and the fish is heavier and has smaller wings than the bird? For this reason the fish is not moved from its place by the swift currents of the water as is the bird by the fury of the winds amid the air; and in addition to this we may see the fish speeding upwards on the very course down which water has fallen abruptly with very rapid movement, after the manner of lightning amid the incessant clouds, which seems a marvellous thing. And this results from the immense speed with which it moves which so exceeds the movement of the water as to cause it to seem motionless in comparison with the movement of the fish. The proportion of the said movements is as one is to ten; the movement of the water being as one and that of the fish ten and exceeding it therefore by nine. Therefore although the fish has the power ten it is left with the power nine, for as it leaps up the descent — its power being ten and the water taking away one from it — nine remains.
This happens because the water is of itself thicker than the air and in consequence heavier, and therefore it is swifter in filling up the vacuum which the fish leaves behind it in the place from whence it departs, and also the water which it strikes in front of itself is not compressed as is the air in front of the bird but rather makes a wave which by us movement prepares the way for and increases the movement of the fish, and for this reason it is swifter than the bird in front of which the air is condensed. c.a. 168 v. b
HOW OXEN FEED ON TALL PLANTS
Oxen in order to feed on the leaves of tall slender plants such as
young poplars and the like are in the habit of raising themselves up, so
that they stride with their legs across the base of the plant and press
continually forward in such a way that the plant, being unable to bear
up against the oppressive weight, is obliged to give way and bow down
its lofty top. c.a. 297 r. b
I With drawing of moth]
The pannicola flies with four wings, and when those in front are
raised those behind are lowered.
But it is necessary for each pair to be of itself sufficient to sustain the
whole weight.
When the one is raised the other is lowered.
In order to see the flying with four wings go into the moats and you
will see the black pannicole. c.a. 377 v. b